Evidence of Evolution(Biology)

Rock fossils are created when three events occur: dead organisms are buried in --- hard tissues ------; the material that surrounds the remains------to form rock.

1) Sediment 2)Mineralize 3)harden

The fossil record shows that early species of horses were generally ______ in size, but many lineages since about 30 million years ago exhibit substantial change toward ______ in size.

1) Small 2) Increase

Place the series of events that must occur to produce a rock fossil in order, starting at the top.

1. Organism become buried in sediments 2. Hard tissues (such as bones) mineralize 3.Surrounding sediment hardens into rock.

Early horses inhabited woody areas where they probably browsed leaves and escaped predators by dodging through openings; this explains why those animals had -------feet and ------legs.

Broad Short

these are similarities between species due to common ancestry.

Homologous Structure

Which of the following best distinguishes vestigial from homologous structures?

Homologous structures are functional, while vestigial structures have no function.

Structures that are derived from a common ancestor but with different appearance and function are called -------structures, while-----structures refers to structures that have little or no function but were functional in an ancestor.

Homologous, Vestigial

Match the different types of anatomical evidence for evolution to an example.

Homology: Vertebrate forelimbs Embryonic Development: Lanugo Vestigial Structures: Human Coccyx

Typically, how are species on islands related to species on a nearby continent?

More Closely

Match the type of rock dating with its description.

Relative Dating: Rocks are dated based on their position Absolute Dating: Rocks are dated based on changes in their isotopic Composition.

How has rock and fossil dating changed since Darwin's times?

Relative dating was used in the past; today we use absolute dating.

What types of species are most likely to be able to disperse to an island (choose all that apply)?

Species that drift Species that fly Species that float

Natural selection does not always produce perfectly working adaptations, because it can only work on the genetic variation present in a population.

True

Some species have anatomical features that have no apparent function but resemble structures of their presumed ancestors; these anatomical features are called

Vestigial Structures

Two types of structures in adult organisms that provide anatomical evidence for evolution are ----- and-----structures.

Vestigial, Homologous

The short legs and broad feet of early horses made them well adapted to their habitat which was

Wooded Areas

Structures that have evolved separately but look very similar exhibit ------- , evolution; in contrast, structures that evolved through modification from a common ancestral trait are ------ structures

convergent homologous

When two species from different lineages independently evolve similar characteristics because they occupy similar environments, we observe ______.

convergent evolution

One of the best studied examples of evolutionary change is that of the -----family. This family includes zebras and donkeys, among other animals.

equidae

The forelimbs of vertebrates are an example of-------structures, while the human appendix is an example of a -------structure.

homologous structure Vestigial Structures

The fossil record reveals that during the last 25 million years most of the lineages in the horse family have exhibited a rapid and substantial ------- in size

increase

Even though there are gaps in the fossil record, some of the most direct evidence for evolution comes from fossils called ______ fossils that illustrate how certain major transformations in life forms occurred. Select all that apply.

intermediate transitional

ll modern members of the horse family are large--------, legged ---------running animals adapted to living in open -------,

long,fast,grasslands

The feet of modern horses have , ----- toe(s); in contrast, early horses had------toe(s) on their front feet and----- toe(s) on their hind feet.

single four three

Island species are usually most closely related to

species on nearby continents

Fast swimming marine predators such as dolphins, sharks, and tuna, have a ------- body shape that minimizes------ in the water.

streamlined friction

The evolution of members of the horse family is

well-documented by the fossil record.

Fossils include

-specimens in amber -remains preserved in rocks -specimens preserved in permafrost -specimens preserved in dry caves

What are some fossil findings in recent years that have bridged major gaps in our understanding of vertebrate evolution?

A four legged aquatic mammal that links marine mammals to their terrestrial ancestors. Tiktaalik, a species that is transitional between fish and amphibians. A fossil snake with legs that links modern snakes to the lizards from which they descended.

Which of the following are typical characteristics of all modern members of the horse family?

Adapted to grasslands Long legs Fast runners

are similarities between species due to convergent evolution.

Analogous Structures

What type of evidence for evolution is provided by fossils

Direct

------are the preserved remains of once living organisms.

Fossils

Some species, for example, frogs, are very sensitive to saltwater and therefore have almost no chance of island colonization. Why is saltwater so harmful to these animals?

It causes those animals to dehydrate.

Early horses had four toes on the front feet and three toes on the hind feet, all encased in fleshy pads. What statement correctly describes how the toes have changed during the evolution of modern horses?

Modern horses have a single toe enclosed in a bony hoof.

How has the fossil record changed since Darwin?

Today the fossil record is far more complete.

How are traits produced by convergent evolution different from homologies?

Traits produced by convergent evolution have not evolved from a common ancestral trait, while homologies have

Today, fossils have been found that link

all major groups of vertebrates

Fossils that contain characteristics of two separate groups of organisms are called -------fossils.

transitional

In recent years, scientists have discovered remarkable fossils, such as a four-legged aquatic mammal and a snake with legs. These are examples of

transitional fossils