Sound Ideas: A Dolphin Leaps

by Carl Strang

The wild world provides a wealth of potential metaphorical material that artists long have used to express their insights. Today’s recording is a song I wrote back in 1997 when I learned of the serious illness of a friend, Jim Niemeyer. Jim passed away a few months later. I share the song now, as the anniversaries of my parents’ deaths last April approach.

Ted and Chuckie Strang on their wedding day

Ted and Chuckie Strang on their wedding day

Mom and Dad with their three grandchildren

Mom and Dad with their three grandchildren

 

Literature Review: Human Evolution

by Carl Strang

Human. Photo by Linda Padera.

Human. Photo by Linda Padera.

Kimbel, William H., et al. 2014. Ardipithecus ramidus and the evolution of the human cranial base. Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1322639111  From a ScienceDaily article. The base of this skull of the 3.4-million-year-old species Ardipithecus ramidus places it in the Australopithecus-human line and separates it from chimpanzees and other apes. The shape features may reflect a change to a more upright posture, or the early reorganization of the brain. Earlier studies had indicated that Ardipithecus was arboreal but also could walk upright on the ground.

Ashton, N., et al. 2014. Hominin footprints from Early Pleistocene deposits at Happisburgh, UK. PLoS ONE 9(2): e88329. doi:10.1371/journal.pone.0088329 They describe footprints of hominins estimated to be 850,000 years old, in sediments of an age where flint tools have been found, and establishing the earliest evidence of hominins outside of Africa. A combination of pollen analysis and stratigraphy (e.g., the footprints are beneath glacial sediments) established the age.

Vernot, Benjamin, and Joshua M. Akey. 2014. Resurrecting surviving Neandertal lineages from modern human genomes. Science 343:1017-1021. Gibbons, Ann. 2014. Neandertals and moderns made imperfect mates. Science 343:471-472. The Gibbons article is a news review describing Vernot and Akey’s study, which showed that though Neandertals and modern humans interbred, there were costs to the hybridization. Only a small amount of Neandertal genetic material has persisted in Europeans and East Asians as a result, mainly genes connected with keratin function, and so affecting skin color, waterproofing, and resistance to cold, helping modern humans to survive in more northern latitudes. They looked at whole genomes of several hundred European and Asian people, and found that collectively they preserve about 20% of the Neanderthal genome (each individual has only 1-3%).

Huerta-Sánchez, Emilia, et al. 2014. Altitude adaptation in Tibetans caused by introgression of Denisovan-like DNA. Nature, DOI: 10.1038/nature13408 From a ScienceDaily article. They looked at the genetics of these high altitude dwellers, and found that the main adaptation that allows them to live in low oxygen without heart problems comes from a gene their ancestors got through the Denisovans. The individuals who first moved into the area had some in their number descended from a modern human-Denisovan cross, and those people had a selective advantage in that environment.

Rasmussen, Morten, et al. 2014. The genome of a Late Pleistocene human from a Clovis burial site in western Montana. Nature 506 (7487): 225. DOI: 10.1038/nature13025 They worked up the genome of the only skeleton ever found in association with Clovis tools, that of a boy less than 2 years old found in a burial. His family and relatives are found to be ancestral to all Native Americans, and connected to Asian ancestors. The boy shares about 1/3 of his genes with the Baikal boy whose genome was sequenced in 2013, with the rest coming from east Asians, that blend happening before emigrating across the Bering Sea land bridge. The Clovis culture developed after the people were established in the New World, well before the 12,600-year age of the newly sequenced genome.

Singing Insects on TV

by Carl Strang

Last September, several of the participants in St. Joseph County’s Bendix Woods Bioblitz were interviewed for that park district’s series of nature-related television programs. Evie Kirkwood, a national leader in the heritage interpretation field, was the interviewer. I was one of the interviewees. My segment recently was televised, in a program that included another on pollination, and one featuring the Field Museum’s Jim Louderman, who also will be participating in our Centennial Bioblitz in DuPage County in June. The program can be viewed HERE. The segments can be selected individually.

The first stop of my segment had both fall field crickets and Japanese burrowing crickets singing, but the latter’s song is more prominent in the audio pickup. I did not mention the Japanese burrowing cricket because I did not confirm its identity until the next day.

Japanese burrowing cricket at Bendix Woods

Japanese burrowing cricket at Bendix Woods

Sound Ideas: Green-striped Grasshopper

by Carl Strang

We are within two months of the start of the singing insect season in the Chicago region. Opening day is marked by the first displays of the green-striped grasshopper.

Male green-striped grasshopper

Male green-striped grasshopper (females usually are green)

These grasshoppers get their early start because they overwinter as nymphs, and so can mature quickly in the spring. Their displays, which qualify them as singing insects, consist of short flights in which they rattle their wings, producing a buzzing sound:

That this is a display is demonstrated by the fact that when they are flying to avoid the pursuit of a possible predator, they do not make that sound.

Literature Review: Pleistocene and Holocene

by Carl Strang

Today’s notes are from last year’s literature on the recent ice ages and subsequent prehistoric times. Some are biological in focus, others relevant to past and present climate change.

Coyotes once were bigger and more carnivorous than they are today, according to the following study.

Coyotes once were bigger and more carnivorous than they are today, according to the following study.

Meachen, J.A., A.C. Janowicz, J.E. Avery, and R.W. Sadleir. 2014. Ecological changes in coyotes (Canis latrans) in response to the ice age megafaunal extinctions. PLoS ONE 9(12): e116041. doi:10.1371/journal.pone.0116041 They measured coyote skulls from 29,000 years ago (La Brea tar pits) to present day, and found a transition from features associated with predation specialization to the present-day omnivory. Another study had found in addition a decrease in body size. They interpret this as a change in predator interactions. When the much larger dire wolf was the other dominant canid, and megafauna were abundant, coyotes could make a good living as specialist predators. Megafauna loss, and associated dire wolf extinction, opened the door for gray wolf immigration from Europe. This new, smaller predator was similar ecologically, but at the same time larger than the coyote, forcing a coyote niche shift to a more generalized diet.

Maher, K., and C.P. Chamberlain. 2014. Hydrologic regulation of chemical weathering and the geologic carbon cycle. Science 343:1502-1504. Kerr, Richard A. 2014. How Earth can cool without plunging into a deep freeze. Science 343:1189. The Kerr news article was based on the Maher and Chamberlain paper. The study looked at the mechanism that limits ice age cooling, preventing it from running away to a pole-to-pole glaciation. Volcanoes add carbon dioxide to the atmosphere, warming climate but also dissolving in rainwater, the resultant carbonic acid dissolving rock. The products flow to the sea, are taken up by plankton for skeleton building, and ultimately are buried. This removal process limits carbon dioxide buildup. Most of the dissolved rock is in mountains, and mountain uplift as in the Andes and Himalayas thus is tied to a global thermostat turndown. However, cooling slows the weathering reactions, allowing carbon dioxide to build back up.

Pena, Leopoldo D., and Steven L. Goldstein. 2014. Thermohaline circulation crisis and impacts during the mid-Pleistocene transition. Science 345:318-322. They found evidence for a profound change in oceanic circulation patterns corresponding to the change in glacial cycling from 41-thousand-year to 100-thousand-year durations. They conclude that “North Atlantic ice sheets reached a milestone in size and/or stability” that led to the ocean circulation change, resulting in a greater carbon dioxide drawdown, increased polar glaciation, and setting the pattern for the following 100,00-year cycles.

Guil-Guerrero, J.L., et al. 2014. The fat from frozen mammals reveals sources of essential fatty acids suitable for Paleolithic and Neolithic humans. PLoS ONE 9(1): e84480. doi:10.1371/journal.pone.0084480 They analyzed the fat chemistry of frozen woolly mammoths, horses and bison from Siberia. The fats were judged to be nutritionally good for human hunters of the time (41,000-4400 years ago). Furthermore, the fats of mammoths and horses were like those of hibernating mammals. The authors suggest that the mammoths and horses hibernated in similar fashion to present-day Yakutsk horses, which move little and mainly stand in sleeping positions during the coldest weather. The mammoth fatty acids suggest derivation from certain lichens in the diet.

Willerslev, Eske, et al. 2014. Fifty thousand years of Arctic vegetation and megafaunal diet. Nature 506 (7486): 47. DOI: 10.1038/nature12921 A large, multi-national team went into Pleistocene sediments and mummified gut contents, and used reference DNA from herbarium specimens to characterize vegetational changes over the past 50,000 years. They found that the last ice age caused a significant alteration of northern plant communities, greatly reducing forbs while increasing grasses and woody plants. Many of the megafauna herbivores such as woolly rhinoceros and woolly mammoth depended on the forbs for their protein content, and the authors believe that the failure of forb-rich communities to re-form after the ice receded contributed to or even caused megafaunal extinctions. No mention was made of human hunting in the ScienceDaily article describing the study.

Hoffecker, J. F., S. A. Elias, and D. H. O’Rourke. 2014. Out of Beringia? Science 343 (6174): 979. DOI: 10.1126/science.1250768 They reviewed cores taken from the Bering Sea and found that Beringia was not a barren grassland through the glacial times but had significant areas of tundra shrubs and trees. Animals including elk and moose likely lived there, and the likelihood of long-term human occupation seems good. This could provide a way that the ancestors of Native Americans could have been isolated from Asians for the 10,000 years, between 25,000 and 15,000 years ago, accounting for the genetic differences comparisons show. Beringia was not glaciated, and summers may well have been like those of today, though winters would have been severe. When the glaciers opened a way by melting, the 15,000-year Native American presence in the continent began as the Beringians moved in.

Sound Ideas: Vegemite

by Carl Strang

“Vegemite” entered the American popular vocabulary in the early 1980’s, thanks to the song “Down Under” by the rock band Men at Work. One of the goals of my trip to Australia was to have lunches built around Vegemite sandwiches. As this is a biological product, and my lunches were experiments in new foods, I don’t feel I am stretching this blog’s mission too much by sharing here the song that resulted from those experiments.

Yes, I brought some back from Australia. And yes, haven’t opened them in over a decade. The song explains why.

Yes, I brought some back from Australia. And yes, haven’t opened them in over a decade. The song explains why.

The didjeridu is a notoriously difficult instrument to mike properly. I did my best. Here’s the chorus:

Vegemite, Vegemite, Vegemite, it’s a legendary substance and a pure delight. If you have no sense of taste or smell I’m sure you’ll agree that a Vegemite sandwich is ecstasy.

(I know I have a few Australian readers. Please don’t feel insulted. A common Australian attitude toward Vegemite was summed up by a woman who exclaimed with delight, upon seeing the diverse breakfast spread at one of the motels where I stayed: “Oh, you have Vegemite and everything!”).

 

Literature Review: Paleogene Period

by Carl Strang

The dramatic departure of the Mesozoic Era and its dinosaurs (as well as a large proportion of other life forms) opened an immense volume of ecological space which was filled by mammals, birds and other diversifying descendants of the survivors. The following are notes from some of last year’s published studies of those early post-Mesozoic epochs.

Blonder, B., et al. 2014. Plant ecological strategies shift across the Cretaceous–Paleogene boundary. PLoS Biol 12(9): e1001949. doi:10.1371/journal.pbio.1001949

Chase, J.M. 2014. A plant’s guide to surviving the Chicxulub impact. PLoS Biol 12(9): e1001948. doi:10.1371/journal.pbio.1001948 This study (interpreted in the Chase paper) found that slow-growing evergreen plants were selected against by the “impact winter” effects of the end-Cretaceous impact event. Plant species with faster growth, cheaper expendable leaves, and thus a quick response to changing and fluctuating conditions, had an advantage and better survival.

The following study suggests that all leaf miners, at least in half the continent, went extinct with the end of the Cretaceous. And yes, that is a poison ivy leaf with 4 leaflets.

The following study suggests that all leaf miners, at least in half the continent, went extinct with the end of the Cretaceous. And yes, that is a poison ivy leaf with 4 leaflets.

Carvalho, Mónica R., et al. 2014. Insect leaf-chewing damage tracks herbivore richness in modern and ancient forests. PLoS ONE 9 (5): e94950. DOI: 10.1371/journal.pone.0094950  They looked at fossil leaf mines, and concluded that all miners went extinct in western North America with the end of the Cretaceous. Newly evolved leaf mining species appeared within 1 million years.

Wilf, Peter, and Ignacio H. Escapa. 2014. Green web or megabiased clock? Plant fossils from Gondwanan Patagonia speak on evolutionary radiations. New Phytologist DOI: 10.1111/nph.13114 They examined a new array of plant fossils and found them to be significantly older than molecular clock studies had indicated they would be. This result points to a need to reconsider molecular dating. It also supports the idea that plants dispersed among the southern continents by continental drift more than by rafting, which had been supported by the younger ages of evolutionary diversification suggested by the molecular dating.

Solé, F., et al. 2014. Dental and tarsal anatomy of ‘miacis’ Latouri and a phylogenetic analysis of the earliest carnivoraforms (mammalia, Carnivoramorpha). Journal of Vertebrate Paleontology, 34(1): 1-21. As described in a ScienceDaily article. They studied fossils (teeth and ankle bones) of a European mammal, Dormaalcyon latouri, from the early Eocene of Belgium, and concluded it is a basal carnivore. It appears to have been arboreal, which implies a continuous forest connecting Eurasia with North America at the time which provided a corridor for carnivore immigration to North America (the age and location suggests that carnivores first evolved in Europe). At the same time it is derived enough to imply that there were early carnivores in the late Paleocene as well.

Rose, Kenneth D., et al. 2014. Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India. Nature Communications 5: 5570 DOI: 10.1038/ncomms6570 As described in a ScienceDaily article. They found fossils bridging Perissodactyla with earlier mammalian groups, from around 56 million years ago, when India still was an island drifting toward Asia. This suggests that the group originated there during that period of isolation. It has been speculated that primates likewise started there, though that has yet to be determined.

Mayr, G., and V. Wilde. 2014. Eocene fossil is earliest evidence of flower-visiting by birds. Biology Letters 10 (5): 20140223. DOI: 10.1098/rsbl.2014.0223 As described in a ScienceDaily article. They describe a 47-million-year-old fossil bird with stomach contents dominated by diverse pollens, and with anatomy consistent with nectar feeding, and conclude that this is the oldest known bird species that visited flowers.

Return to the Platform

by Carl Strang

One of my annual rituals is to go out in mid-February and seek the nest of the great horned owl on the preserve that I am monitoring (Mayslake for the past several years). This year that task proved to be much too easy, as the birds returned to the location of their nest in 2012. That was when they made the arguably poor choice of laying their eggs on top of a squirrel nest. It worked as long as the female was incubating quietly, but after the eggs hatched the nest began to fall apart from all the comings and goings. One of the babies fell to the ground and we rescued it. After it was checked out and cleaned up at the Willowbrook Wildlife Center, it was returned and its dubious home was placed on a more solid platform.

Mike Wiseman did the honors.

Mike Wiseman did the honors.

Ultimately one youngster branched.

Ultimately one youngster branched.

The platform remained, and we hoped the owls would use it, but they apparently did not nest in 2013, and last year they nested in an unknown location not far from the stream corridor marsh. Maybe a couple years’ accumulation of fallen leaves was needed to make a suitable foundation. Hard to say. In any case, on January 28 I found this:

Just enough of her peeks out to reveal that glare so typical of an incubating owl.

Just enough of her peeks out to reveal that glare so typical of an incubating owl.

That was as much as she showed. Sometimes it was less.

Those feather tufts are a good image to plant in your mind if you are going hunting for a great horned owl nest. Sometimes they are all you will see.

Those feather tufts are a good image to plant in your mind if you are going hunting for a great horned owl nest. Sometimes they are all you will see.

We had a blizzard a few days after I found the nest. She seemed well protected in that platform, so I hoped the storm didn’t drive her off the nest. That was what I believed happened in 2011 when the Groundhog Day Stormageddon blizzard brought in a couple feet of snow in short order. After around 40 days the owls abandoned the nest that year. This year I was counting the days. Last Friday she was on the nest. On Monday she was gone. I checked a couple times through this week, but sadly we appear to have a repeat of the 2011 failure. This is why great horned owls live so long, so as to have multiple opportunities to produce the young that will replace them in the population.

 

Sound Ideas: Katydids that “Katydid”

by Carl Strang

The name “katydid” has come to cover a wide range of singing insects, most of whose songs do not sound anything like that name would suggest. Today I wish to share recordings of two species which seem to say something like that name. Both are common in the region. First up is the oblong-winged katydid:

Oblong-winged katydid

Oblong-winged katydid

The next recording is of a common true katydid. Though this individual has only two syllables per song, some have three to match the syllables in “katydid,” and others have 4 (“katy didn’t”) or more.

Common true katydid

Common true katydid

Ah, summer.

 

Literature Review: Bird Evolution

by Carl Strang

As I mentioned last week, the Mesozoic Era is a perennial hot topic in paleontological research. Lately, a hot topic within that hot topic has been the evolution of birds (plus the lead-up to the first birds in the feathered dinosaurs, some studies of which were included in last week’s listing). Here are notes from some studies published last year.

Dinosaur descendant

Dinosaur descendant

Mitchell, Jonathan H., and Peter J. Makovicky. 2014. Low ecological disparity in early Cretaceous birds. Proceedings of the Royal Society B, DOI: 10.1098/rspb.2014.0608 As described in a ScienceDaily article. They did an intensive study of a collection of fossil birds from China, early in the Cretaceous Period around 125 million years ago, when birds were a relatively new addition to the fauna. They concluded that the collection probably is a reasonably good approximation of what was there, and that it shows a remarkable lack of diversity. The size range and dietary breadth were limited, and large birds and water birds were missing. Most birds were sparrow to crow sized. There were some differences from today, as some species retained teeth or bony tails. Indications are that they lived in the forest and on the ground, and ate mostly insects and seeds. Though some of this limitation might have resulted from competition with established groups such as pterosaurs, the authors point to the lack of time for evolutionary diversification to occur as the main constraint.

Brusatte, Stephen L., Graeme T. Lloyd, Steve C. Wang, and Mark A. Norell. 2014. Gradual assembly of avian body plan culminated in rapid rates of evolution across the dinosaur-bird transition. Current Biology, DOI: 10.1016/j.cub.2014.08.034 As described in a ScienceDaily article. They looked at the evolutionary development of various structural components of birds, such as feathers, wishbone and wings. The elements of the bird body appeared separately over a very long period of time in the fossil record, with a slow convergence on the ultimate bird body plan in the line of theropod dinosaurs that led to them. Thus there is no stepwise appearance of the first bird. However, once the first birds had evolved, their diversification and continued evolution happened much more rapidly, demonstrating the advantages of that body plan.

Puttick, Mark N., Gavin H. Thomas, and Michael J. Benton. 2014. High rates of evolution preceded the origin of birds. Evolution, DOI: 10.1111/evo.12363 As described in a ScienceDaily article. They looked at the fossil record and used computer models to calculate rates of evolution of various traits. Two features essential to birds, small size and elongated forelimbs, began to appear 20 million years prior to Archaeopteryx, so that there were many species of small feathered dinosaurs (paraves) capable of flight well before the first birds appeared.

Meredith, R.W., G. Zhang, M. T. P. Gilbert, E. D. Jarvis, and M. S. Springer. 2014. Evidence for a single loss of mineralized teeth in the common avian ancestor. Science 346 (6215): 1254390 DOI: 10.1126/science.1254390 This portion of the whole-genome bird comparison study found that all modern birds point to a single common ancestor that lost the capability to grow teeth more than 100 million years ago, over a short span of time developing mutations inactivating 6 genes involved in enamel and dentin formation.

Lee, Michael S.Y., Andrea Cau, Darren Naish, and Gareth J. Dyke. 2014. Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds. Science 345:562-566. They did a detailed statistical study across the entire range (time and taxonomic) of theropod dinosaurs, and found a trend over the Mesozoic of reduction in body mass, culminating in the birds. This set the stage for other skeletal modifications that made birds possible.

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