THE MEANING OF ‘SPECIES’

8/13/2019 THE MEANING OF ‘SPECIES’

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THE MEANING OF ‘SPECIES’ 1. The conventional, present-day understanding of what we mean by species isgiven in lines 7, 8 & 9. What is that definition?

It is a group of living organisms consisting of similar individuals capable ofexchanging genes or interbreeding.

2. As a definition it is quickly destroyed by the reference to Blue Whales and Fin Whales (lines 9-17). How do these two species contest the conventionaldefinition?

The Blue Whale and the Fin whales species contradict the conventional definition because they can breed with each other in order and are capable of producingfertile offspring without the necessity of being part of the same species.

3. In the 3rd paragraph, (lines 18-37), the two concepts of what a species iscompared. What was the species concept prior to the 1930‟s?

Before the 1930’s there was a problem with defining how the animals weredifferent. They were all just considered different kinds of living organism butthere was no real classification of the animals themselves.

Although not named in the text, who do you think was the greatest advocate ofthis concept?

Charles Darwin. But I believe that it all change with Mayr and Dobzhansky.

4. What was/is the species concept introduced by Dobzhansky and Mayr in the1930‟s?

Prior 1930‟s species concept was just different kinds of living things but there was a problem with defining “different”. The concept that they introduced wasthe concept that the animals could be classified into artificial collections ofindividuals.

5. Darwin was not particularly concerned by the concept of a species. Why not?

Darwin was not concerned about the concept of species due to the fact that hedoes not consider species real entities. Because he saw individuals were the unitsof his new theory of evolution, not species.

6. Given the probable several million of mostly tiny organisms not yet describedon this planet, what problems face a natural historian who thinks he/she hasfound, and wants to name a new species?



The problem with this is that the person who believes that they have found a newspecies can’t be sure because they would have to find another animal of that samespecies and see if they can breed and produce fertile offspring. If not then it isprobably a hybrid. Plus there are probably also millions of other species alike that

you would have to try with to see if it is a new species. Only then can u be sureand nobody is going to try something as pointless as seeing a “ NEW SPECIES”mate with a million other species.

7. What do you understand by the term subspecies? (Line 70)

A subspecies is a small group belonging to the same group as its big species group but it the animals themselves with different characteristics making them asubspecies of the original species group.

8. Organisms may differ or be similar “in their morphology, anatomy and DNA”(line 74), and their?

Breeding Groups

9. The variation in beaks of the 13 sub species of Darwin finches on Galapagos arecited as a good example of natural selection working to make groups of birdsdistinct one from another, rather than reproductive isolation (lines 83-98).Explain the argument being used.

Darwin explains that the cause of the species remaining different is due to naturalselection and due to reproductive isolation. This species of finches owns differentcharacteristics such as their beaks that help them adapt to their environment. For

example eating habits.

10.(I) Why do hybridizing species challenge the conventional BSC? (Lines 99-113).

These species were ignored because they did not meet the requirements of beinga species as cohesive, reproductive units.

(II) And why is the US Endangered Species Act (1973) a problem fortaxonomists? (Lines 119-120)

They exclude hybrids because they are seen as outsiders, which do not truly belong to the environment and natural order.

(III) Red wolves and coyotes are known to have hybridized (lines 126-129). (iii)Can you name another two species, which can successfully hybridize?

Humans, Orangutans



11. Darwinian evolution theory focuses very much upon “species and clusters ofrelated individuals” (lines 156-157). What therefore is the evolving unit in Darwinian evolution theory?

Species owning different characteristics should be considered different species

altogether.

12. Selection forces act upon the “small cluster of related individuals” butspecifically, and in genetic terms, what is it that is being selected for or against?

The strongest, superior and most dominant are selected.

13. Given this discussion, what would now be your „best‟ definition of a species?

Species are a group of individuals which own different characteristics but similarDNA, anatomy, and morphology, they can mate with each other to give a fertile

offspring which is capable of reproducing with others of the same species but canalso produce a hybrid.

14. What is the fundamental event in the DNA of an organism that ultimately canenable evolution of a new organism with different characteristics to appear?

Organisms bond together making new characteristics in their future offspring, which will

enable the evolution of the species.

15. For one organism, give a full classification (from Kingdom to species), sayingat each point of classification, what characteristics enable the grouping of theorganism.

Cheetah:

Acinonyx Jubatus

Kingdom: animaliaPhylum: ChordataClass: MammaliaOrder: CarnivoraFamily: FelidaeGenus: Acinonyx

Species: A. Jubatus

Stephen Sheedy



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THE MEANING OF ‘SPECIES’