Homologous structures provide evidence for common ancestry, while analogous structures show that similar selective pressures can produce similar adaptations (beneficial features). Similarities and differences among biological molecules (e.g., in the DNA sequence of genes) can be used to determine species’ relatedness.
Why do similarities between two species suggest common ancestry?
Even though two different species may not look similar, they may have similar internal structures that suggest they have a common ancestor. That means both evolved from the same ancestor organism a long time ago. Common ancestry can also be determined by looking at the structure of the organism as it first develops.
What provides embryological evidence that two species share a common ancestor?
Which of these cases provides embryological evidence that two species share a common ancestor? Two species might have similar skeletal structures that have different functions. Common structures with different functions suggest that the species share a common ancestor that also had a similar structure.
Which evidence of evolution best illustrates that the two species had a common ancestor?
Today, scientists can compare their DNA. Similar DNA sequences are the strongest evidence for evolution from a common ancestor.
What is the significance of vertebrates sharing similarities at the embryo stage of development?
Similarities in structure among distantly related species are analogous if they evolved independently in similar environments. They provide good evidence for natural selection. Examples of evidence from embryology which supports common ancestry include the tail and gill slits present in all early vertebrate embryos.
Why do vertebrate embryos show similarities between organisms that do not appear in the adults?
Comparative embryology shows similarities between organisms that do not appear to be similar as adults because many features of embryos disappear by adulthood. For example, all vertebrate embryos have a tail and gill slits, but these disappear by adulthood in many vertebrates, including humans.
What does the similarity of embryos suggest?
This shows that the animals are similar and that they develop similarly, implying that they are related, have common ancestors and that they started out the same, gradually evolving different traits, but that the basic plan for a creature’s beginning remains the same.
In what stages of development of the vertebrates show similarities?
All developing vertebrates appear very similar shortly after gastrulation. It is only later in development that the special features of class, order, and finally species emerge.
Why do all vertebrates have similar forms during development?
The reason why all vertebrates have very similar forms during development it is because they reflect their evolutionary history or phylogeny.
Scientists infer that species with similar body structures and development patterns inherited many of the same genes from a common ancestor True True or False? Scientists can compare protein structure to determine how closely two species are related.
When does isolation occur, new species can form?
When a group of individuals remains isolated from the rest of its species long enough to evolve different traits, a new species can form True What are three ways that isolation can occur? Three ways isolation can occur is by a mountain range, ocean or wave, or volcano, even or river, or stream.
How are scientists able to tell the size of an animal?
Scientists infer whether the animal walks alone or by four or two feet and the size and shape by looking at the footprints What are three ways that the remains of organisms have been preserved?
What was one of Darwin’s most important observations?
What were Darwin’s important observations? The diversity of organisms, the remains of ancient organisms, and the characteristics of organisms Nice work! You just studied 78 terms!