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What era did organisms arise?

The first known single-celled organisms appeared on Earth about 3.5 billion years ago, roughly a billion years after Earth formed. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago.

Which of the following organisms first evolved during the Cambrian explosion?

This period lasted about 53 million years and marked a dramatic burst of evolutionary changes in life on Earth, known as the “Cambrian Explosion.” Among the animals that evolved during this period were the chordates — animals with a dorsal nerve cord; hard-bodied brachiopods, which resembled clams; and arthropods — …

What events occurred at the beginning of the Cambrian period approximately 542 million years ago?

The Cambrian explosion, or less commonly Cambrian radiation, was the relatively short evolutionary event, beginning around 542 million years ago in the Cambrian Period, during which most major animal phyla appeared, as indicated by the fossil record.

Are remains of plants and animals which are considered an evidence of evolution quizlet?

the trace (preserved) remains of plants, animals, and other organisms from the distant past: examples include bones, teeth, impressions, and leaves. Provides evidence for evolution because they suggest that an organism changed from using the structure to not using the structure.

What is the evidence of evolution quizlet?

– The fossil record is a record of change in a species over time. – Geologists found that fossil organisms on the bottom, or older, layers were more primitive than those in the upper, or newer, layers. – These findings supported Darwin’s concept of descent with modification.

What are the main differences between homologous and analogous structures?

Homologous structures share a similar embryonic origin; analogous organs have a similar function. For example, the bones in the front flipper of a whale are homologous to the bones in the human arm. These structures are not analogous. The wings of a butterfly and the wings of a bird are analogous but not homologous.

Which pair is an example of analogous structures?

One example of analogous structures is the wings of bats, flying insects, and birds. Analogous structures are easily identifiable when wings of different organisms are studied. For example, the wings of a bird and insect perform the same function, i.e., flying or movement through the air.

What are some examples of analogous terms?

Analogous terms are those which apply to two different things that both have something in common and something that separates the two terms. The term “backup,” which refers both to a computer backup and police backup, is an example of two similar but different terms using the same word.

What are examples of homologous structures?

A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of four-legged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod structure.

What are two homologous structures?

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. They are considered homologous structures because they have a similar underlying anatomy.

What is another name for homologous structures?

In evolutionary biology, organisms with such similarities could indicate a common ancestor or same developmental origin. The condition or state in which structures are homologous but they do not function the same way is referred to as “homology” (plural: homologies). Synonym: homologues. Compare: analogous structures.

Which one defines homologous structures?

The definition of a homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn’t necessarily share the same purpose. An example of a homologous structure is the human arm as compared to the wing on a bird. noun.

What is the origin of homologous structures?

Homology is a relationship defined between structures or DNA derived from a common ancestor and illustrates descent from a common ancestor. Analogous structures are physically (but not genetically) similar structures that were not present the last common ancestor.

What is an example of vestigial structures?

Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human appendix and vomeronasal organ; and the hindlimbs of the snake and whale.

What type of evolution is homologous structures?

Similar body parts may be homologous structures or analogous structures. Both provide evidence for evolution. 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.

What does evolved mean?

: to change or develop slowly often into a better, more complex, or more advanced state : to develop by a process of evolution.