Evolution Flashcards
What is biodiversity?
A measure of the number of species on the planet.
What defines species?
A group of organisms that can interbreed and produce fertile offspring when homologous chromosomes can pair at meiosis.
What are the two most biodiverse areas on the planet?
Coral Reef and Tropical rainforest.
One example of the least biodiverse area on the planet
Desert
What is the general rule of diversity?
More diversity of plant life means more diversity in animal life.
What do fossil records show?
That most species are now extinct.
What does bottleneck mean?
Where a number of species drop followed by rapid diversification
Why does bottleneck happen?
species adapt to fill vacant niches
What does Darwins Finches prove?
Adaptive radiation
What is extinction
Loss of species, when species disappear.
How did Darwin prove adapted radiation
On Galapagos Islands, Darwin realised that all the finches had different shaped beaks. Darwin said that all 14 species evolved from one comment ancestor. And that all the finches were able to colonise as there were no interspecific competition by other birds and no intraspecific competition because there was plenty of food.
For speciation to occur (due to natural selection) what must there be?
- Variation brought by random mutations
- Overproduction of offspring
- Individuals must have a struggle for survival
What will happen to those individuals best suited for survival?
Pass on their genes and continue over many generations. leading to different groups forming from the original species.
What is adaptive radiation?
The emergence of several new species from a common ancestor introduced into an environment
What is evolution?
Evolution is the process by which new species are formed from pre-existing ones over a very long period of time.
What does taxonomy mean?
The scientific study of the diversity of living organisms.
What does taxon mean?
A group of organisms sharing basic features
What does classification mean?
The organisation of living organisms into groups according to their evolutionary relationships.
What is the classification system and how are organisms classified?
The modern classification system is called the phylogenetic hierarchy and organisms are classified using a phylogenetic tree.
What does hierarchy mean?
A large group of organisms split into smaller and smaller groups.
What does phylogenetic mean?
The way organisms are grouped in the hierarchy reflects how the group of organisms are related.
Who made the classification systen?
Carl Linnaeus in the 18th century
What does the hierarchical system of classification include?
Kingdom, Phylum, Class, Order, Family Genus, Species
What does the hierarchical system of classification include?
Kingdom - Animal, Plant, Fungi, Protoctista and prokaryote
Phylum - Arthropods, Chordates, Annelids etc
Class - Insects, Mammals, Fish, Amphibians etc
Order - A group of related families
Family - A group of similar genera
Genus - A group of closely related species
Species - a group of organisms that can interbreed and produce fertile offspring because of homologous chromosomes that could be used during meiosis.
What is the Human Classification?
Kingdom - Animalia Phylum - Chordata Class - Mammalia Order - Primates Family - Hominidae Genus - Homo Species - Sapiens
What is the binomial naming system?
Many living organisms have a common name and often changes. Linnaeus’ system of classification overcomes this problem as each organism is given a Latin name based on its genus and species e.g. humans are homo sapiens.
3 reasons why classification is important
1 - To make the study of living organisms more manageable
2 - Support ideas of evolution
3 - Allow scientists to communicate with one another
What is the biochemical method for comparing how species are related?
Gel Electrophoresis
What is the five kingdom classification?
Prokaryotic - Unicellular, Bacteria/algae Protoctista - Eukaryotic Fungi - Eukaryotic Plants - Eukaryotic Animal - Eukaryotic
How to prove common ancestry
- DNA base sequencing - the more similar the base sequence, the more closely related they are
- Protein amino acid sequencing - The more similar the sequence the more closely related (use gel electrophoresis)
Species of humans
Homo Habilis - between 2.4 - 1.4 mya - Height - 1.0-1.5m - brain capacity - 600-800 cc Homo Erectus - between 1.8 mya - 70000 ya - height - 1.3-1.5m - brain capacity - 750-1250 Homo Sapiens neanderthalensis - between 400000 - 40000 ya - height - 1.5-1.7m - brain capcity - 1200-1350 Homo sapiens - between 130000 - 60000 ya - height - 1.6 - 1.85 m - brain capacity - 1200 - 1700 cc
What is the multiregional model?
This theory proves that the homo Erectus migrated out of Africa to Europe and Asia about 2 million years ago. Basically concluding that Homo Sapiens evolved directly from the Homo Erectus in different parts of the world.
What is the Out of Africa model?
This model suggests that only the African descendants of H.Erectus gave rise to modern humans. All regional descendants, including the Neanderthals, became extinct without contributing to the gene pool of modern man.
What is convergent evolution?
The tendency of evolutionarily unrelated organisms to acquire similar structures. E.g bat wing/insect wing
What is divergent evolution?
Evolutionarily related organisms develop structures with a common origin into structures that have different functions e.g human hand/bird wing
What are fossils
Preserved dead remains of plants and animals.
What is paleontology?
The study of plants and animals of the geological past, as represented by their fossil remains.
What is continental drift?
The movement of the earth’s continents relative to each other by appearing to drift across the ocean bed
What is phylogeny?
The evolutionary relationship between organisms
What is a gene pool?
The total number of alleles in a particular population in a particular time.
