Speciation

What is the significance of "living fossils"?

"Living fossils" are modern species that have changed little from their ancient ancestor (example is the lungfish). It gives us information about what was alive millions of years ago which is on the fossil record. All the aspects missing from a fossil we can get from a living fossil, which can helps learn about the fossils descendents

3 Domains

(Eu)bacteria (eubacteria) , Archaea (archaebacteria) , eukaryotic (everything else).... eubacteria and archaebacteria are prokaryotic vs the third domain which has all of the eukaryotes

What are the different reproductive barriers?(8)

1.Mechanical Isolation: two species cannot breed because they are anatomically (structurally) incompatible 2.Behavioral Isolation: two species attract mates by using different mating signals or courtship rituals 3. Temporal Isolation: to species breed at different times. They could be separated by as little as a few hours, by seasons, or even by years 4.Habitat Isolation: two species live in the same geographical area but do not meet because they live in different specific habitats in that area 5.Geographic Isolation: two species live in different geographic areas, and never meet in the wild 6.Gametic Isolation: two species cannot breed because their gametes (eggs and sperm) cannot interact, even when they come into contact with each other 7.Reduced Hybrid Viability: two species can breed, but the hybrid offspring produced do not live to reproductive age 8.Hybrid Sterility: two species can breed and the hybrid offspring survive, but these hybrids are sterile

How do you make and use a dichotomous key?

A dichotomous key is a series of two statements that become increasingly more specific as you move down the key, eventually leading you to the classification of an organism.

How do eukaryotes and prokaryotes differ?

A prokaryote is an organism whose cells do not contain a membrane bound nucleus or organelles. A eukaryote is an organism whose cells have a membrane bound nucleus and organelles.

What is a taxonomist?

A scientist/biologist who groups organisms into categories

Define species. What are the problems associated with defining distinct species?

A species can be defined as a group of organisms that are able to naturally reproduce in the wild to produce fertile offspring. However, there is difficulty defining distinct species because speciation is a continuous process, meaning that species are constantly changing.

What is a species?

A species is a group of organisms that are able to naturally reproduce in the wild; they can contribute to a common gene pool

What is adaptive radiation?

Adaptive radiation is the diversification of a group of organisms into forms filling different ecological niches. There are available niches in an environment that can be exploited by new species. An example of this is the finches on the Galapagos islands: all 16 species diverged from a common ancestor. The finches adapted to different food sources (such as big and small seeds) and nesting sites. Because there is a different type of food source it means that there is a niche open so the finches are exploiting a different part of the environment/different niche.

How do you name a species?

All species are named through binomial nomenclature, meaning that they have two names. The first name is the genus and the second name is the species. This name is always italicized and the first name is capitalized.

What is allopatric speciation and how does it happen?

Allopatric speciation is speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. A reproductive barrier must be introduced for the two groups to become two different species. When two species become isolated, different selective pressures in the different areas will account for different adaptations between the two groups. it can happen if there is a highway built in the middle of a population

Give two examples of how the number of characteristics shared by members of a group changes as you proceed from species to kingdom.

An example of how the number of characteristics shared by members of a group changes as you proceed from species to kingdom, would be the Thomomys bottae (common name: gopher). Firstly looking at the species of the Thomomys bottae, there is no other species shown on the chart that have similar characteristic (although there are some). Moving along to the genus, Thomomys, there is again nothing similar, but as you move long again to the family, there is a similar family called the Sciuridae. These two similar families are both in the same order: Rodentia. The further one moves along this spectrum the more broad the grouping is, so the order rodentia has all of the rodent families, and so there are many, many species in it. Next the order rodentia is placed into class mammalia, which has every mammal in it, which is even more broad. Next the class is in the phylum Chordata, along with a large variety of species, and finally this phylum is in the kingdom animalia, which essentially has all animals in it.

Six different kingdoms

Anagram: Even Amy Prefers Fewer People Around -Archaebacteria : prokaryotic bacteria which live in extreme habitats (extremophiles), single celled, heterotrpoh, cell walls made of different polysaccharides and proteins, with no peptidoglycan. Many archaebacteria have cell walls made of the polysaccharide pseudomurein -Eubacteria : prokaryotic, more successful distribution (found everywhere, live in conditions thought to be similar to conditions on early Earth), single celled, heterotroph, cell wall with peptidoglycan -Protista: eukaryotic, larger bacteria, single cell, some multicell forms, heterotroph and autotroph, -Fungi: eukaryotic, multi celled, have a cell wall composed of a tough carbohydrate called chitin, absorptive heterotrophs, mostly saprophytic -Animals: eukaryotic, consumers, mobile @ some point in life cycle, multicelled, develop from embryos, digestive heterotrophs -Plants: eukaryotic, photosynthetic producers, multicellular, have cell walls composed of cellulose, develop from embryos

What is binomial nomenclature, and what function does it serve?

Binomial nomenclature is a system of calling things by two names. Each species uses binomial nomenclature to be identified. The first word in each name of a species is the genus name and it is always capitalised, and the second word describes the particular species. Together the two words form the scientific name for the species and it should always be written in italics. Binomial nomenclature is important because it gives one name to a specific species while identifying what genus it is, and having one name creates a universal way to identify species without mixing up a few.

Using an example, describe the process of sympatric speciation.

Establishment genetic divergence w/o geographic isolation Reproductive isolation develops Example would be polyploidy because multiple plants within a population can end up with the same polyploidy number. They can then reproduce with each other but not with the original plants or any other plants. As a result, they become biologically isolated from the original group of plants and are considered a different species. It is a type of sympatric speciation, which means that it occurs without geographic isolation.

Indicate which kingdoms are characterized by a particular characteristic (information from chart in practice test)

Eubacteria-- cell wall with peptidoglycan, heterotroph, Archaebacteria-- heterotroph Protista--eukaryotic, heterotroph Fungi-- eukaryotic, multicellular, heterotroph, cell wall with chitin, digestive heterotroph Plantae--eukaryotic, multicellular, cell wall with cellulose Animalia-- eukaryotic, multicellular, heterotroph, digestive heterotroph

How would you expect an orthodox classification to differ from a cladogram? Explain.

For an orthodox classification, biologists must examine many organisms and try to judge which characteristics were most useful for classifying them and phenetics. Therefore, orthodox classifications are more general and based on morphological information. Whereas a cladogram shows the common traits between descendants and ancestors, and is more specific..

What condition must organisms meet in order to be considered members of the same species?

For organisms to be considered members of the same species, they must be able to naturally mate and breed with one another to produce fertile offspring. Members of one species usually cannot produce fertile offspring with members of another species.

What information does a phylogeny contain?

Fossil record, morphology, lifestyles (behavior), habitats of representatives, and biochemical comparisons with other groups (this is also the evidence for evolution)

sympatric speciation

Genetic divergence in the absence of a geographical barrier

describe the process of allopatric speciation.

Geographic isolation Genetic divergence occurs Reproductive isolation develops

Who was Carolus Linnaeus?

He was the father of modern taxonomy. He developed the modern system of classification: binomial nomenclature. He grouped species based on morphological differences.

Define the term homologies and explain why they're important to classification. Explain how species maintain their distinctness.

Homologies are structures that develop following the same "logic" or ancestral genetic plan. They are important in classification because classification focuses on structures that indicate a related evolutionary ancestry, and not just similarities; homologies demonstrate this perfectly. Also because it's easy to observe in organisms and fossils, and fossils are the only evidence we are ever likely to have of extinct species. Chemical homologies (like similarities in the structures of cellular polymers) are also evidence of close evolutionary relationships. Therefore, even though structures may look very different on the outside, in the chemical level and bone structure level, they are similar and teach us a lot about common ancestors. Species maintain their distinctness because most of the time they cannot breed with other species to provide a fertile offspring (post-zygotic barrier)

What is convergent and divergent evolution?

In convergent evolution, two species that are not necessarily closely related develop similar features often as a result of adaptation to similar conditions (analogies). Divergent evolution is when two organisms have a common ancestor but do not develop similar features (homologies).

What are isolation mechanisms, and how do they operate? Give examples

Isolation mechanisms are mechanisms that isolate populations to allow for speciation to occur. Examples are geographical isolation, habitat isolation, temporal isolation, gametic isolation, mechanical isolation, behavioral isolation, hybrid sterility, and reduced hybrid viability.

What is the biological species concept?

It is a concept that states that species are groups of actually or potentially interbreeding populations, which are reproductively isolated from other such groups

What is a phylogeny?

It is an evolutionary tree depicting the evolutionary history/relationships within a group of organisms

Why are islands good places to find examples of adaptive radiation?

Mostly because they tend to be isolated. The chance of finding one species that arrived and then adapted into exploiting different niches of the environment is higher because you don't see as much inter genus competition and are much more likely to see intra species competition. Ex. finches.

List factors that result in changes in classification systems.

New data results, gain in new information leads to a more complex relationship among organisms, as our understanding improves, biologists/ scientists may feel like changes must be made to the systems, new technology

How do new species form?

New species are formed through speciation. Speciation occurs when identical populations diverge and reproductive isolation develops. Species also separate when potential mates do not meet, potential mates meet but do not breed, or potential mates meet, breed, but DO NOT produce viable offspring (all reproductive barriers). Speciation most commonly occurs through allopatric speciation and sympatric speciation.

Phenetics vs Cladistics

Phenetics are the method where a taxonomist compares organisms on the basis of as many characteristics as possible, and then gives each pair of organisms a similarity score based on the number of traits they share; phenetics give an equal importance to all characteristics. Cladistics are a method of classification for organisms that takes account of only those shared characteristics that can be proved to have originated in the common ancestor of a group of species during an evolution. So, in phenetic classification, all of the characteristics are looked at, but in cladistic classification only shared characteristics are looked at

What is polyploidy? What is its connection to speciation?

Polyploidy is the duplication of chromosomes, which occur accidentally during cell division. The offspring generally cannot mate successfully with plants having the parental number of chromosomes. They can reproduce asexually or often can mate with other polyploid offspring. In this way, they establish a new species. Polyploidy doesn't really happen in animals, because when a cell goes wrong in animals it kills itself. Polyploidy isn't a mutation, because a mutation is change in a dna molecule, and polyploidy isn't a change in dna, just a change in the chromosome number.

Compare punctuated equilibrium and gradualism.

Punctuated equilibrium and gradualism both are patterns of evolution. Punctuated equilibrium is where there are long periods of stasis, with no change, and that is punctuated by busts or morphological change and speciation. Gradualism is small changes over a long period of time that end up causing speciation. Gradualism happens over time, while punctuated equilibrium is sudden, rapid change. Gradualism is the darwinian view of evolution - small changes occur over time creating a different species Equilibrium - is a burst (20-30 thousand years) change, rapid change (polyploidy) Opposite ends of a spectrum

What is sympatric speciation?

Sympatric speciation is genetic divergence in the absence of a geographical barrier. An example of sympatric speciation are cichlid fish, for although they are members of the same species, fish of one color only want to mate with the other fish of that color (behavioral isolation).

How does the Kingdom Protista differ from the other Kingdoms?

The Kingdom Protista consists mostly of microscopic unicellular eukaryotes, and they are larger bacteria. Some protists, such as kelp, are multicellular organisms that can be more than 10 cm long, but these organisms do not differentiate into many types of cells, as many plants and animals do. Protist differs from the other Kingdoms because it's single celled and because they're both autotroph and heterotroph. Protista differs from other Kingdoms as it made up of mostly unicellular large bacteria, which are eukaryotes and both heterotrophic and autotrophic. Other kingdoms are either heterotrophs or autotrophs, while Protista is both.

How does the Linnaean system of groups and subgroups express the idea of degree of relatedness?

The Linnaean system uses homologies to group species into larger and more general categories. Species with many similar characteristics are grouped in the same genus. Similar genera are grouped in the same family. Species with similar appearance and behavioral characteristics are grouped into the same order. The species are then grouped into class, then phylum (division), and then kingdom. Kingdom is the most inclusive category, and species is the most exclusive.

List characteristics used to separate organisms into kingdoms

The characteristics used to separate organisms into kingdoms are: Whether the organism is a prokaryote or a eukaryote, Whether the organism is an autotroph or heterotroph, Whether the organism develop from an embryo, Whether the organism is unicellular or multicellular, General structure and function, Cell walls

What are the different taxa into which species can be classified?

The different taxa are kingdom, phylum, class, order, family, genus, species. Kingdom is the most inclusive, and species is the least inclusive.

Describe the most important difference that separates prokaryotes and eukaryotes.

The most important difference that separates prokaryotes from eukaryotes is that their cell structures are very different. Eukaryotes also have a membrane bound nucleus and organelles, whereas prokaryotic cells do not contain a membrane bound nucleus or organelles.

What is the speciation continuum?

The speciation continuum is the continuum which shows how much two species have diverged, whether the species are early, mid, or late on the continuum is based off of the strength of the reproductive isolation barriers

Can homologies suggest that many species evolved from a few species? Defend your answer through examples.

Yes, homologies by definition are structures with different functions, but share evolutionary origin. For a dolphin flipper and bat wing, the bone structure is the same, but they have different functions. Another example is a human hand and a cat paw.

gradualism

a model of evolution in which change takes place at a slow, steady rate, resulting in a steady increase in biological diversity

punctuated equilibrium

a model of evolution in which speciation occurs in spurts of relatively rapid change followed by long periods of stablility

cladistics

a systematic method of classification that relies on shared characteristics not found in other organisms

autotroph

an organism that forms its own food molecules (carbon compounds) from abiotic materials

heterotroph

an organism that obtains carbon compounds from other organisms

prokaryote

an organism whose cells do not have membrane-enclosed nuclei or organelles; a moneran (bacterium)

eukaryote

an organism whose cells have a membrane-enclosed nucleus and organelles; a protist, a fungus, a plant, or an animal

pre-zygottic barrier

any heritable feature that prevents interbreeding 1. Ecological species specialized enough never occur in same microenvironment in habitat 2. Behavioral Elaborate courtship & mating rituals keep organisms apart 3. Temporal Breed different times of year 4. Mechanical Incompatibility between body parts 5. Gamete mortality Gametes incompatible at molecular level

post-zygotic barrier

barriers that prevent speciation after two organisms have sexually reproduced 1. Developmental Abnormal development, usually cease before birth 2. Hybrid inviability Not survive to age reproduce 3. Hybrid sterility Hybrid vigorous, but not able to leave offspring (Such as mules)

phylogeny

evolutionary history of an organism (evolutionary tree) Reflects evolutionary relationship between species Based on: (Evidence for evolution) Fossil record Morphology Life-styles Habitats of representatives Biochemical comparisons with other groups

cladogram

evolutionary tree diagram (phylogeny) which groups taxta by shared derived characteristics

zygote

fertilised egg

species

groups of interbreeding natural populations that are reproductively isolated from other such groups Populations that interbreed and produce fertile offspring or contribute to a shared gene pool belonging to the same species (Breed naturally, create fertile offspring, isolated from others)

taxon

groups of organisms at particular level in classification system

saprophyte

heterotroph that lives on dead organic matter (eg fungus)

extinction

irrevocable loss of a species mass extinctions have occurred 20 or more times in the past

polyploidy

multiple copies of chromosomes caused by mistakes in cell division

derived characteristics

novel feature that evolved in just one species and is shared ONLY by its descendants Only shared derived characteristics considered informative

Explain the statement "Populations evolve, not individuals within a population."

one cannot evolve, but a population evolves.

monophenetic group

refers to common ancestor and all descendents

gamete

sex cell (sperm or egg)

clade

single branch based on phylogeny

allopatric speciation

speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interfered with genetic interchange

physiology

the branch of biology that deals with the normal functions of living organisms and their parts (organs, tissues, or cells); the way in which a living organism or bodily part functions

phenetics

the method where a taxonomist compares organisms on the basis of as many characteristics as possible, and then gives each pair of organisms a similarity score based on the number of traits they share; phenetics give an equal importance to all characteristics (orthodox classification)

speciation

the origin of new species as a result of evolutionary processes

fitness

the size of one's genetic contribution to the size of the next generation's gene pool

taxonomy

the theories and techniques of describing, grouping, and naming living things; Science of classification

binomial nomenclature

the two-word naming system used in taxonomy, consisting of the Latin genus and species of an organsism; Genus: always capitalized, underlined or italicised Species: Never capitalized, always underlined or italicised

niche

the way an organism fits into an ecosystem; from natural selection, a niche is the result of morphological, physiological, and behavioral adaptations; what an organismdoes in an evironmrnt- its job (such as finches eating seeds vs insects)

adaptive radiation

when organisms diversify rapidly from ancestral species into a multitude of new forms; the diversification of a group of organisms into forms filling different ecological niches