BIOLOGY UNIT 17 quiz

Darwin’s key ideas?

“Individuals with certain types of inherited variation are better suited for their environment.”

“Descent with modification, living species are descended from those older.”

Natural selection

A process by which some individuals better adapted to their environment survive and reproduce. Survival of the fittest.

Vestigial structure

An evidence of evolution: structure inherited from an ancestor but has become “useless“ lost size and purpose.

Comparative embryology

Similar patterns in the early stages of embryonic development, shows evidence of common ancestry.

Analogous structures

Body parts that serve same functions but has different structures, such as the wings of a butterfly and a bird.

Homologous structures

Similar structures but may serve different purposes, such as whale flippers and human hands.

DNA Molecular evidence

-similar genetic code, homologous genes and molecules proves common descent

-DNA and RNA are nearly identical in every organism, evidence of common ancestry

-Homologous hox genes

Fossils

Evidence of how organisms changed over time, by presenting various different organisms fossils, structures. Descent with modification

Biogeography

The study of how animals and plants were distributed geographically around the world.

Thomas Malthus

Hypothesized that human population was ket in check by diseases, famines and wars.

Wallace line

An imaginary boundary that divides the species of Asia and Australia. Going though island Lombok Biogeographical evidence.

Wallace line species

Species of the west(Asia)- placental mammals, elephants tigers, rhinos and orangutans.

Species of east(Austrelia)- Marsupials, monotremes and unique birds. Reptiles, komodo dragons.

Why couldn’t the animals cross?

There was a very deep sea straight caused by tectonic plates that the animals could not cross, they just evolved on their own sides, and later could not get used to the other sides so stayed where the developed.

Adaptation

Can involve body parts, structure and behavior. Adapt to environment over time.

Does Natural selection make organisms “better”?

No, it does not move in a fixed direction, and it just has to be good enough for the organism to pass that trait to offspring.

Tree thinking

Over may generation, different sets of changing environment can cause multiple adaptations and make a single species split into two or more nee species. “A single tree of life links all living things”

Evolution

Change in allele frequencies in a population over time, driven by mechanisms such as natural selection, genetic drift, gene flow and mutations,

Mutation

A random change in DNA that causes new alleles in a population. Must be heritable so change happens in gametes, germ line cells.

Gene flow

Movement of alleles between populations though migration.

Genetic drift

Random change in allele frequencies due to chance events.

How did Darwin develop his idea from Thomas Malthus?

He borrowed the idea of competition for limited resources and used it to explain natural selection, those with advantage survive most.

Lamarck’s ideas

Organisms can acquire traits, and the acquired traits can be passed down to offspring.

Galapagos birds

Birds on different islands has different variations, such as beaks size.

Marsupials

Native Australian animals.

What did Darwin notice about organisms from different places?

Different yet ecologically similar species inhabited seperated but ecologically similar habits.

Galapagos tortoises

Tortoise living on different islands could be told apart, they has different variations.