Scivillage.com Casual Discussion Science Forum

https://theconversation.com/we-solved-th...ded-163774

EXCERPTS: For over 50 years now, scientists have known that, despite their reputation, not all fish are cold-blooded. Some shark and tuna species, the white shark and the Atlantic bluefin tuna, have evolved the ability to warm parts of their bodies, such as their muscle, eyes and brain.

[...] It turns out that warm-blooded fish can swim 1.6 times faster than cold-blooded fish. This is some of the first direct evidence of the evolutionary advantage of being warm-blooded.

This extra speed provides advantages when it comes to things like predation and migration. It’s likely that this makes them better hunters or travellers. The faster swim speeds also aid the fish in identifying prey. The quicker they swim, the faster an image moves across their eye, allowing them to process and identify the image – perhaps of prey – faster than slower counterparts.

It has previously been suggested that these warm-blooded fishes may be better able to deal with changing ambient temperatures by stabilising their body temperatures. This would be useful under current climate change scenarios, such as global ocean warming.

That may be the case, but our results indicate the ability to warm their bodies doesn’t allow them to occupy a broader temperature or depth ranges. This means we may have been overstating the resilience warm-blooded fish have for facing changing ocean temperatures... (MORE - missing details)

Never really dawned on me before but the current state or makeup of the body of any organism must have some historical significance behind it. I’m thinking evolution along with its survival adaptations also indicates a history of the earth. Every organism may currently possess an adaptation or vestige(s) of a former epoch that their ancestors evolved to get through changing environmental conditions, not just adaptations for hunting or being hunted. To survive until today may have required some interesting traits and current status may reveal what the Earth was like during certain epochs of change.

Do warm blooded fish indicate a past era’s environmental condition? Sounds like there must be a science here where people can at least make educated guesses on past Earth by studying evolutionary body traits. Is there a science that studies this? I’m not thinking fossils in the rock sense but actual physical traits that exist today. Can we go backwards in time, learn about Earth environmental history by looking at the current features of, not maybe all creatures?

(Jul 7, 2021 01:26 PM)Zinjanthropos Wrote: [ -> ]Never really dawned on me before but the current state or makeup of the body of any organism must have some historical significance behind it. I’m thinking evolution along with its survival adaptations also indicates a history of the earth. Every organism may currently possess an adaptation or vestige(s) of a former epoch that their ancestors evolved to get through changing environmental conditions, not just adaptations for hunting or being hunted. To survive until today may have required some interesting traits and current status may reveal what the Earth was like during certain epochs of change.

Do warm blooded fish indicate a past era’s environmental condition? Sounds like there must be a science here where people can at least make educated guesses on past Earth by studying evolutionary body traits. Is there a science that studies this? I’m not thinking fossils in the rock sense but actual physical traits that exist today. Can we go backwards in time, learn about Earth environmental history by looking at the current features of, not maybe all creatures?

Maybe. Right now it's largely tracking down the original locations of populations, the interactions of the latter, construing their past diet phases from physiology, potentially tweezing out the lost existence of extinct relatives from the surviving species, and how they adapted to situations already known from geologic records.

- - - - -

https://www.earthtouchnews.com/natural-w...cient-dna/

In her own research, Lynch turns to DNA for assistance. She studies North American martens – small carnivores related to weasels – ranging in age from several decades to 15,000 years old. Not only does their DNA help her sort out the relationships between the animals' various ancient populations, but by constructing the extended marten genealogy, she can also identify the location and timing at which new populations arose and new traits evolved. Combining this evolutionary info with the geologic record, she can then piece together how the animals responded to environmental changes such as Ice Age glacial cycles.

- - - - - -

Ancient DNA data fills in thousands of years of human movement and genetic adaptation in Africa
https://www.ancient-origins.net/news-evo...tic-021626

- - - - - -

Taking a bite out of tooth evolution: Frogs have lost teeth more than 20 times
https://www.sciencedaily.com/releases/20...135714.htm

Florida Museum of Natural History researchers analyzed CT scans of nearly every living amphibian genus to reveal that frogs have lost teeth over 20 times during their evolution, more than any other vertebrate group. Some frog species may have even re-evolved teeth after losing them millions of years before.

Researchers also found a correlation between the absence of teeth in frogs and a specialized diet on small insects, such as ants and termites. Their analysis of frogs' amphibian relatives, the salamanders and obscure wormlike animals known as caecilians, showed these groups retained teeth on both upper and lower jaws throughout their evolutionary history.

- - - - - -

Ancient DNA holds clues to climate change adaptation
https://www.sciencedaily.com/releases/20...102519.htm

Thirty-thousand-year-old bison bones discovered in permafrost at a Canadian goldmine are helping scientists unravel the mystery about how animals adapt to rapid environmental change.

- - - - - -

A seedy slice of history: Watermelons actually came from northeast Africa
https://www.sciencedaily.com/releases/20...161825.htm

Using DNA from greenhouse-grown plants representing all species and hundreds of varieties of watermelon, scientists discovered that watermelons most likely came from wild crop progenitors in northeast Africa. The study corrects a 90-year-old mistake that had previously tied watermelons to South Africa. The genetic research is consistent with newly interpreted Egyptian tomb paintings that suggest the watermelon may have been consumed in the Nile Valley as a dessert more than 4,000 years ago.

- - - - - -

Ancient horse DNA reveals gene flow between Eurasian and North American horses
https://www.sciencedaily.com/releases/20...130826.htm

A new study of ancient DNA from horse fossils found in North America and Eurasia shows that horse populations on the two continents remained connected through the Bering Land Bridge, moving back and forth and interbreeding multiple times over hundreds of thousands of years.

- - - - - -

Origin story: Rewriting human history through our DNA
https://www.princeton.edu/news/2019/12/1...gh-our-dna

For most of our evolutionary history — for most of the time anatomically modern humans have been on Earth — we’ve shared the planet with other species of humans. It’s only been in the last 30,000 years, the mere blink of an evolutionary eye, that modern humans have occupied the planet as the sole representative of the hominin lineage.

But we carry evidence of these other species with us. Lurking within our genome are traces of genetic material from a variety of ancient humans that no longer exist. These traces reveal a long history of intermingling, as our direct ancestors encountered — and mated with — archaic humans. As we use increasingly complex technologies to study these genetic connections, we are learning not only about these extinct humans but also about the larger picture of how we evolved as a species.

Joshua Akey, a professor in the Lewis-Sigler Institute for Integrative Genomics, is spearheading efforts to understand this larger picture. He calls his research method genetic archaeology, and it’s transforming how we’re learning about our past. “We can excavate different types of humans not from dirt and fossils but directly from DNA,” he said.