When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. What is meant by "Common descent"? - Biology Stack Exchange

    biology.stackexchange.com/questions/108952/what-is-meant-by-common-descent

    B is the most recent common ancestor of 1,3, 2,3, and 1,2,3. The thick black line coming down from B in the figure represents the connection to B's ancestors. All of those ancestors are common ancestors of 1,2,3, but none are the most recent common ancestor of 1,2,3. The most recent common ancestor of cellular life is the last universal common ...

  3. Ancestral vs derived alleles. An ancestral allele or an ancestral trait (depending on whether you look at the phenotype or a t the genotype) is the trait/allele that was carried by the common ancestor of the taxon you consider. For example: as you may know the taxon Reptilia includes lizards, snakes, turtles, birds, mammals and some other ...

  4. evolution - What is the evidence that plants and animals had a...

    biology.stackexchange.com/questions/79972/what-is-the-evidence-that-plants-and...

    Darwin did propose that all extant organisms have a common ancestor: Therefore, on the principle of natural selection with divergence of character, it does not seem incredible that, from some such low and intermediate form, both animals and plants may have been developed; and, if we admit this, we must likewise admit that all the organic beings which have ever lived on this earth may be ...

  5. terminology - Explaining "paraphyly" for the layperson? - Biology...

    biology.stackexchange.com/questions/111543/explaining-paraphyly-for-the-layperson

    Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, except for mammals and birds. Other commonly recognized paraphyletic groups include fish, monkeys, and lizards. If you want to use any of these labels: fish, monkeys, lizards, reptiles, it ...

  6. All life on Earth (bacteria, archaea, eukarya) is thought to have evolved from a common ancestor, or last universal common ancestor (LUCA).

  7. evolution - How are the wings of birds, pterosaurs and bats...

    biology.stackexchange.com/questions/71458/how-are-the-wings-of-birds...

    Or put another way, the common ancestory of bats, birds and pterosaurs had front limbs, but those front limbs weren't wings. Compare with the "wings" of flying fish, which does have a common origin with that of birds/bats/pterosaurs: both developed from the pectoral fins of their bony fish common ancestor.

  8. There are some good answers here already but they mostly focus on whether similarities in the DNA sequence of organisms imply common ancestry. This misses something much more fundamental that is very strong evidence for this particular question: we all use essentially the same configuration of machinery to store genetic information and turn it ...

  9. The most important of these is sequence similarity (usually amino acid sequence) since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity. $\endgroup$ –

  10. evolution - Classification and differences between homologous ...

    biology.stackexchange.com/questions/65906/classification-and-differences...

    Homoplastic traits can be analogous, meaning they developed independently without any common ancestor or commmon initial trait, or can be traits that arose due to convergence, where species with the same (distance/close) ancestor independently developed the traits. Please evaluate whether my understanding is correct.

  11. When was the last common ancestor of pig and human?

    biology.stackexchange.com/questions/41945

    Last common ancestor is about 97.5 Million Years Ago. TimeTree.org Pig vs. Human. That being said, they are close enough to us that they are a vector for influenza viruses that are able to make the jump to human pretty easily. Also we use their tissue as a homologue for human in forensic research. We also use valves from pig hearts to replace ...