3 Persons are tagged with #biology

#biology

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devevo@diasp.org
7B'JaJaDa

#biology #apes #earlyApes #evolution
In an open woodland, Morotopithecus bishopi climbs a tree with an infant on its back and a juvenile below. Corbin Rainbolt
https://www.smithsonianmag.com/science-nature/early-apes-lived-on-savannahs-not-in-forests-180982182/
Early Apes Lived on Savannas, Not in Forests
Two new studies suggest that 21 million years ago African primates frequented edge habitat and fed on leaves
…East Africa’s early apes were not hanging onto forests as lush woodlands gradually gave way to grasslands. Instead, early apes were already taking advantage of more open habitats that shifted between wet and dry seasons through the year…
May 23, 2023

Early Apes Lived on Savannas, Not in Forests

Two new studies suggest that 21 million years ago African primates frequented edge habitat and fed on leaves

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brainwavelost@nerdpol.ch
brainwavelost

The Cat Who Would Be A Dog: Are We All Trans?

“Identity is like wine. You cannot judge it by the label — only by tasting”.

Wow! Deeeeppp. I didn’t understand what that meant! So I knew he was saying something profound….

#LGBT #LGBTQ #LGBTI #LGBTIQA #LBGTQIAH #ALL? #identity #cats #dogs #normopathy #condition #biology

What do you think about that article?

We are all Trans

As you remember from my article on the Year of the Cow, er, Ox…. , Deke knows about more than just cows — he know about all sorts of…

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devevo@diasp.org
7B'JaJaDa

#biology #evolution #marsupials #mammals
Marsupials Are 'Far More Evolved' Than Other Mammals, Even Humans
Nature 29 May 2023 By Tessa Koumoundouros
A new study challenges the idea that marsupials are more 'primitive' than mammals by showing their development has changed more than mammals since they last shared an ancestor.
https://www.sciencealert.com/marsupials-are-far-more-evolved-than-other-mammals-even-humans

Marsupials Are 'Far More Evolved' Than Other Mammals, Even Humans

A new study challenges the idea that marsupials are more 'primitive' than mammals by showing their development has changed more than mammals since they last shared an ancestor.

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devevo@diasp.org
7B'JaJaDa

#biology #genetics #evolution
Tweaking Just a Few Genes Transforms Scales Into Feathers
The feathers, fur, and scales that adorn different members of the animal kingdom may look quite different, but they're all made of the same basic stuff. And, as it turns out, it only takes a relatively simple genetic tweak to produce one instead of the other...
https://www.sciencealert.com/tweaking-just-a-few-genes-transforms-scales-into-feathers

Tweaking Just a Few Genes Transforms Scales Into Feathers

The feathers, fur, and scales that adorn different members of the animal kingdom may look quite different, but they're all made of the same basic stuff.

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kennychaffin@diasp.org
Kenny Chaffin

Now new data suggests comb jellyfish (ctenophores), which, contrary to appearances, are only distantly related to true jellyfish, win "first", despite comb jellyfish having a more complex differentiated nervous system. They're a neat example of how evolution is not a straightforward march toward greater complexity.

https://www.sciencealert.com/we-might-finally-know-what-the-very-first-animals-looked-like

#biology #life

We Might Finally Know What The Very First Animals Looked Like

Researchers have just found a robust answer to the centuries-long mystery of which multicellular animal first existed on Earth.

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waynerad@diasp.org
Wayne Radinsky

The complete genomes of 240 mammal species have been sequenced. Along with a "whole-genome alignment", where they line up the DNA sequences in one species with the equivalent DNA sequence in another species. The researchers identified 4,552 "conserved" regions. When talking about DNA, a region is considered either "fast-evolving" if it changes rapidly, or "conserved" if it stays the same over time. If a region is "conserved", there's probably a reason -- the sequence needs to be the way it is because it encodes some essential function. Knowing that a region is "conserved", however, doesn't tell you what the reason is. It's just a clue that there's something important going on. And just as a region can be "conserved" within a species over time, a region conserved across related species is probably conserved for a reason. But you don't necessarily know what the reason is.

Examining the conserved regions, the researchers found regions that relate to hibernation, olfaction, vocal learning, and brain size. Not only that, but these evolved multiple times -- sort of. For example, hibernation evolved in both bears and bats. But it is thought that the underlying "coding" genes are conserved across mammal species -- it's the non-coding DNA that controls what genes get switched "on" and "off" that is thought to have evolved independently. "Coding" means the DNA encodes proteins which are assembled by ribosomes after the information on the DNA is transcribed to messenger RNA (mRNA) and ferried over to the ribosomes. "Non-coding" DNA doesn't encode for proteins. It was thought to be "junk" before it was realized that often this "non-coding" DNA controls the expression of the "coding" DNA, through such mechanisms as transcription factors.

A highly detailed phylogenetic tree of mammal species was made that resolves disputes in previous phylogenetic trees. The effects of the Cretaceous-Paleogene (K-Pg) extinction, which wiped out the dinosaurs and enabled placental mammals to take over land and rapidly diversify, is measurable in the genomes.

In addition to the 4,552 nearly perfectly preserved regions, 10.7% of the human genome was considered "unusually conserved" across mammal species. 57.6% of coding bases fall into this category, but on the flip side, 80.7% of the bases in this category are non-coding. If that makes you scratch your head, review your Bayes' Theorem: A given B is different from B given A. Given a base known to be coding, there's a 57.6% chance it's in the "unusually conserved" category. Give a base known to be "unusually conserved", there's an 80.7% chance it's non-coding.

Approximately 439,461 candidates for "regulatory elements", regions of non-coding DNA which regulate the transcription of other genes, were identified for further study. In addition, 2,024,062 transcription factor binding sites were found. Transcription factor binding sites. Transcription factors are proteins that turn genes "on" and "off" by controlling their "transcription" from DNA to messenger RNA (mRNA) which goes to the ribosome to control the assembly of a protein.

In addition to finding regions that are the same compared with other mammals, the researchers looked for regions that are different -- the so-called human accelerated regions. Conserved within the human lineage, but different from other mammals, especially our closest relatives, the chimpanzees. These are thought to underlie human-specific traits. Some of these are thought to be neurodevelopmental genes.

There are also human-specific conserved deletions, where short (2-3 base pair) deletions took place. 10,032 of these human-specific conserved deletions were identified. Many of these are believed to affect neurons and nerve tissue and have affected our cognitive function.

For alignment, they created a new machine-learning tool that can align genes even if they underwent translocations (where a gene or part of a gene moves to a different chromosome) or inversions (where a portion of a DNA sequence gets copied in the reverse direction), and works for non-coding regions as well as the parts within coding regions that don't encode proteins but are "start" and "stop" indicators and such ("introns" as opposed to "exons").

They also looked at transposable elements, colloquially known as "jumping genes". These are DNA sequences that change their positions within a genome, sometimes with dramatic effects such as altering the cell's genetic identity or even its genome size. The lowest genomic percentage of transposable elements was found in the star-nosed mole (27.6%), and the largest percentage was seen in the aardvark (74.5%), whose higher transposable element count corresponds with larger genome size.

Finally, they looked at species that are nearing extinction and found the small population sizes decrease heterozygosity and increases the deleterious genetic load, making extinction even more likely. To determine deleterious genetic load, they looked at regions known to be vital in familiar species such as mice.

What makes a mammal? 423,000 newly identified DNA regions guide our genes

#discoveries #biology #genomics #mammals

What Makes a Mammal? 423,000 Newly Identified DNA Regions Guide Our Genes

These elements, dubbed “UNICORNs,” sit close to genes that affect smell, sleep and ways that people and other mammals interact with their surroundings

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waynerad@diasp.org
Wayne Radinsky

Basal metabolic rate (the rate of energy consumption "at rest" without any physical or mental exertion) has declined in the US since the 1980s. Down 220 kcal/day on average for males and 122 kcal/day for females.

We are currently expending about 220 kcal/d less for males and 122 kcal/d less for females

#discoveries #biology #metabolism

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