Chapter-7 Evolution

Had Darwin been aware of Mendel’s work, would he been able to explain
the origin of variations. Discuss.

We are told that evolution is a continuing phenomenon for all living
things. Are humans also evolving? Justify your answer.

Two organisms occupying a particular geographical area (say desert)
show similar adaptive strategies. Taking examples, describe the
phenomenon.

What are the key concepts in the evolution theory of Darwin?

You have studied the story of Pepper moths in England. Had the
industries been removed, what impact could it have on the moth
population? Discuss.

Explain divergent evolution in detail. What is the driving force
behind it?

Name the law that states that the sum of allelic frequencies in a population
remains constant. What are the five factors that influence these values?

"Migration may enhance or blurr the effects of selection". Comment.

Enumerate three most characteristic criteria for designating a Mendelian
population.

When we say "survival of the fittest", does it mean that
a. those which are fit only survive, or
b. those that survive are called fit?
Comment.

How do you express the meaning of words like race, breed, cultivars or
variety?

Gene flow occurs through generations. Gene flow can occur across
language barriers in humans. If we have a technique of measuring specific
allele frequencies in different population of the world, can we not predict
human migratory patterns in pre-history and history? Do you agree or
disagree? Provide explanation to your answer.

State and explain any three factors affecting allele frequency in
populations.

Comment on the statement that "evolution and natural selection are
end result or consequence of some other processes but themselves are
not processes".

The evolutionary story of moths in England during industrialisation
reveals, that 'evolution is apparently reversible'. Clarify this statement.

While creation and presence of variation is directionless, natural selection
is directional as it is in the context of adaptation. Comment.

Why is nascent oxygen supported to be toxic to aerobic life forms?

The scientists believe that evolution is gradual. But extinction, part of
evolutionary story, are 'sudden' and 'abrupt' and also group-specific.
Comment whether a natural disaster can be the cause for extinction of
species.

Louis Pasteur’s experiments, if you recall, proved that life can arise from
only pre-existing life. Can we correct this as life evolves from pre-existent
life or otherwise we will never answer the question as to how the first
forms of life arose? Comment.

Among Ramapithecus, Australopithecines and Homo habilis - who
probably did not eat meat?

By what Latin name the first hominid was known?

Who among the Dryopithecus and Ramapithecus was more man-like?

What is founder effect?

Among the five factors that are known to affect Hardy-Weinberg
equilibrium, three factors are gene flow, genetic drift and genetic
recombination. What are the other two factors?

In a certain population, the frequency of three genotypes is as follows:
Genotypes: BB Bb bb
frequency: 22% 62% 16%
What is the likely frequency of B and b alleles?

When we talk of functional macromolecules (e.g. proteins as enzymes,
hormones, receptors, antibodies etc), towards what are they evolving?

How do we compute the age of a rock?

What is the most important pre-condition for adaptive radiation?

How do we compute the age of a fossil?

Give an example for convergent evolution and identify the features
towards which they are converging.

How do we compute the age of a living tree?

What are we referring to? When we say 'simple organisms' or 'complex
organisms'.

Did aquatic life forms get fossilised? If, yes where do we come across
such fossils?

What were the characteristics of life forms that had been fossilised?

How do Darwin and Hugo de Vries after regarding Mechanism of Evolution?

Give examples to show evolution by anthropogenic action.

(i)In which part of the world, Neanderthal man lived? (ii)What was his brain’s capacity?

(iii)Mention the advancement which Neanderthal man showed over Homo erectus.

Fill up the blanks left in the table showing Era, period and organism.

             Era                          Period         Organisms                                  

Cenozoic                          a             Modern man, Mammals, Birds, rise

                                                                 of  monocot                                  

               b                            Tertiary         Rise  of  first  Primate,  angiosperm  

        Mesozoic                           c              Gingko,  Gnetales                        

               d                            Jurassic        Conifers,  cycads,  Reptiles           

        Paleozoic                          e              Early  reptiles  (extinct)                 

f                            Silurian        Psilophyton

Stanley Miller and Harold Urey performed an experiment by recreating in the laboratory the probable conditions of the atmosphere of the primitive earth.

(i)    What was the aim of the experiment?

(ii)   In what forms was the energy supplied for chemical reactions to occur? (III)  For  how  long  was  the  experiment  run  continuously?  Name  two

products formed.

Classify the following as examples of homology and analogy– (i)      Hearts of fish and crocodile

(ii)   Wings of butterfly and birds

(iii)  Eyes of Octopus and Mammals

(iv)  Tubers of potato and Sweet potato

(v)   Thorns of Bougainvillea and spines of Opuntia

(vi)  Thorn of Bougainvillea and tendrils of cucurbits.

(i)    State the Hardy-Weinberg principle.

(ii)    When there is a disturbance in the Hardy-Weinberg equilibrium, what would it result in?

(iii)  According  to  this  principle,  what  is  the  sum  total  of  all  allelic frequencies?

Distinguish  between  convergent  and  divergent  evolution  giving  one example of each.

Explain Oparin-Haldane theory of chemical evolution of life.

Name the scientist who had also come to similar conclusion as that of Darwin about natural selection as a mechanism of evolution. Which place did he visit to come to conclusions?

Name  the  person  who  proposed  that  population  tends  to  increase geometrically while food production increases arithmetically.

If abiotic origin of life is in progress on a planet other than earth, what should be the conditions there?

For a long time, it was believed that life originated from decaying matter.

What is this theory known as? Name the scientist who experimentally disproved this theory.

Name one fish like reptile that evolved from land reptile about 200 million years ago?

What is Biogeography? How Darwin’s finches provide biogeographical evidence
in favour of evolution.

State in what ways Stanley miller simulated the condition of :-
i) Primitive atmosphere on earth.
ii) Energy source at the time of origin of life .
iii) Formation of organic molecule of life.

Bring out differences between De Vrie’s mutations Darwinian Variations?

Differentiate between convergent & divergent evolution?

A chimpanzee can hold objects by its hand & an elephant by trunk. Are these
organs Analogous or homologous?

What is “Founder’s effect”?

Name the species of human beings which is most closely related to modern man.

Which period is called “Age of Reptiles”.

What are the three different ways in which selection may occur.

Trace the important events or stages of human development?

What are the facts that support Darwin’s theory of Natural selection?

Define natural selection? Who else along with Charles Darwin proposed it as
the mechanism of evolution?

Would you consider wings of butterfly & a bat as homologous or Analogous
& why?

What is speciation? List any two events that lead to speciation?

If you discovered a fossil bird with scales on the body & teeth in the beak.
What would you conclude about its position in the animal kingdom?

What is meant by Gene pool?

Who showed that life comes from pre-existing life?

What provided energy for a biotic synthesis on primitive earth?

What does Hardy weinberg’s principle states? What are the factors
which affects Hardy weinberg’s equilibrium?

Chemical insectides remain useful only for a limited time. Explain with
reference to evolution with a suitable example.

What is Biogenetic law? How does comparative embryology provides
evidences for evolution?

Life originated from the earth’s inorganic atmosphere in the post, but
this no longer happens today. Give two reasons?

Why has natural selection not eliminated sickle – cell anaemia?

What is the study of fossils called? Mention any three points how the
fossils throw light on past life?

Which period is known as “Age of amphibians”?

Name the common ancestor of apes & man?

Name the two scientists who set up a special experiment to prove
Oparin’s theory of origin of life?

What does Oparin – haldane hypothesis about origin of life suggests?

Who were the two scientists that conducted an experiment to synthesise
organic molecule abiotically? How did they provide the probable
condition of the primitive earth in this experiment?

By taking industrial melanism as on example, explain the concept of
natural selection by evolution?

Describe one evidence which decisively proves that birds have evolved
from reptiles?

What is the role of variation in evolution?

Define homologous organs? Give one example of organ homologous to
hand of man?

Name the phenomenon by which rapid speciation takes place?

What is the cause of speciation according to Hugo De Vries?

Name any two vestigial organs found in human body?

Using various resources such as your school library or the internet and discussions with your teacher, trace the evolutionary stages of any one animal say horse.

Can we call human evolution as adaptive radiation?

Describe one example of adaptive radiation.

Practise drawing various animals and plants.

List 10 modern-day animals and using the internet resources link it to a corresponding ancient fossil. Name both.

Find out through internet and popular science articles whether animals other than man have self-consciousness.

Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

Attempt giving a clear definition of the term species

Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.