Species may share
similar physical features because the feature was present in a common ancestor (homologous structures)
. Molecular biology. DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can show how related species are.
Why do different species have similar structures?
The structures are similar
because they evolved to do the same job, not because they were inherited from a common ancestor
. For example, the wings of bats and birds, shown in Figure below, look similar on the outside. They also have the same function. However, wings evolved independently in the two groups of animals.
Homologous structures
are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants.
Why would two different species have similar features?
Different species around the world have similar features. That’s
because they face some of the same selective pressures
. This is called convergent evolution.
What are similar structures with different purposes found in different species known as?
Analogous structures
are body parts of different species that have a similar function. These structures have a similar purpose but can look completely different.
What are the 7 patterns of evolution?
Groups of species undergo various kinds of natural selection and, over time, may engage in several patterns of evolution:
convergent evolution, divergent evolution, parallel evolution, and coevolution
.
What are examples of analogous structures?
Analogy, in biology, similarity of function and superficial resemblance of structures that have different origins. For example,
the wings of a fly, a moth, and a bird
are analogous because they developed independently as adaptations to a common function—flying.
What anatomy is the study of the similarities and differences in organisms structures?
Comparative anatomy
is the study of similarities and differences in the anatomy of different species. It is closely related to evolutionary biology and phylogeny (the evolution of species).
What are 3 examples of homologous structures?
Following are some examples of homology:
The arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale
are homologous structures. They are different and have a different purpose, but they are similar and share common traits.
What are analogous structures?
Analogous structures are
features of different species that are similar in function but not necessarily in structure
and which do not derive from a common ancestral feature (compare to homologous structures) and which evolved in response to a similar environmental challenge.
What are similar species with different characteristics?
- Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. …
- The opposite of convergence is divergent evolution, where related species evolve different traits.
Examples of Convergent Evolution
Both
sharks and dolphins
have similar body forms, yet are only distantly related: sharks are fish and dolphins are mammals. Such similarities are a result of both populations being exposed to the same selective pressures. Within both groups, changes that aid swimming have been favored.
What are similar species?
Key Points. Members of the same species are
similar both in their external appearance and their internal physiology
; the closer the relationship between two organisms, the more similar they will be in these features.
Do humans have analogous structures?
Analogous structures, as pointed earlier, are
structures having a similar or corresponding function
but the two species under probe should not share the same evolutionary origin. The forelimbs of mammals, such as humans and bats, are homologous structures.
What is in common between all species?
Every living creature has
DNA
, which has a lot of inherited information about how the body builds itself. Scientists can compare the DNA of two organisms; the more similar the DNA, the more closely related the organisms.
What are examples of vestigial structures?
Structures that have no apparent function and appear to be residual parts from a past ancestor are called vestigial structures. Examples of vestigial structures include
the human appendix, the pelvic bone of a snake, and the wings of flightless birds
.
