DNA and the genetic code
reflect the shared ancestry of life. DNA comparisons can show how related species are.
Similarities and differences between the “same” gene
in different organisms (that is, a pair of homologous genes) can help us determine how closely related the organisms are. Biogeography. The geographical distribution of species can help us reconstruct their evolutionary histories. Fossils.
DNA and the genetic code
reflect the shared ancestry of life. DNA comparisons can show how related species are.
In a phylogenetic tree, the relatedness of two species has a very specific meaning. Two species are more related
if they have a more recent common ancestor
, and less related if they have a less recent common ancestor.
What kind of evidence is used to determine the relationships between animals?
Fossils
provide evidence that organisms from the past are not the same as those found today, and demonstrate a progression of evolution. Scientists date and categorize fossils to determine when the organisms lived relative to each other.
What are the 5 evidence of evolution?
Five types of evidence for evolution are discussed in this section:
ancient organism remains, fossil layers, similarities among organisms alive today, similarities in DNA, and similarities of embryos
.
What are the evidence for the theory of evolution?
Perhaps the most persuasive fossil evidence for evolution is
the consistency of the sequence of fossils from early to recent
. Nowhere on Earth do we find, for example, mammals in Devonian (the age of fishes) strata, or human fossils coexisting with dinosaur remains.
What has the closest DNA to humans?
The chimpanzee and bonobo
are humans' closest living relatives. These three species look alike in many ways, both in body and behavior. But for a clear understanding of how closely they are related, scientists compare their DNA, an essential molecule that's the instruction manual for building each species.
Humans,
chimpanzees
, gorillas, orangutans and their extinct ancestors form a family of organisms known as the Hominidae. Researchers generally agree that among the living animals in this group, humans are most closely related to chimpanzees, judging from comparisons of anatomy and genetics.
They labeled
chimpanzees
and gorillas as African apes and wrote in Biogeography that although they are a sister group of dental hominoids, “the African apes are not only less closely related to humans than are orangutans, but also less closely related to humans than are many” fossil apes.
What three taxa do all four organisms have in common?
First person to group or classify organisms. … What three taxa do all four organisms have in common?
Kingdom, Phylum, and Class
. Which taxon includes animals with backbones?
To decide wheiher two species are closely related,
scientists can look at the skeletons of the species and at the species' DNA if available
. Similar species have similar bone structure. Changes in bone structure over time can also be seen by the skeleton. For example, the tail cone on a human links us to monkeys.
The existence of extremely similar species may cause local and global species diversity to be underestimated. The recognition of similar-but-distinct species is
important for disease and pest control
and in conservation biology although the drawing of dividing lines between species can be inherently difficult.
How is DNA used as evidence for evolution?
Organisms that seem fairly similar on the basis of comparative anatomy, show more genes in common than organisms that aren't much alike. For example, 96% of the genes in humans and chimpanzees are identical. That two
species and their common ancestor have similar DNA
is strong evidence supporting evolution.
Can you describe why certain extinct plants and animals were not fossilized?
Many plants and animals do not become fossils
because they decompose or are eaten before they can be fossilized
. Organisms decompose quicker when exposed to oxygen. Dead organisms are also more likely to be eaten by scavengers when exposed to the open environment.
Why is fossil evidence usually not enough?
For many reasons, the
fossil record is not complete
. Most organisms decomposed or were eaten by scavengers after death. Many species lacked hard parts, which are much more likely to fossilize. Some rocks and the fossils they contained have eroded and disappeared.
