MYTUTOR SUBJECT ANSWERS

418 views

Explain the formation of a new species

Speciation (the formation of a new species) can be broken down into a few concise steps.

The most important step is the isolation of two populations. This usually occurs because of physical factors such as a lake drying up and being separated into two smaller lakes.

As a result the fish in each lake are no longer able to breed with the fish in the other lake, resulting in no alleles being transferred between the populations.

Within each population mutations (random changes in the base sequence of DNA) will occur. But importantly since the changes are random the mutations that occur in each population will be different.

Similarly since both populations are now in different environments, physical characteristics of each enviroment such as water temperature will vary. As a result a mutation which may be favourable to cooler water conditions such as a thicker fat layer, may be favourable to one population of fish but detrimental to the other where the water is warmer.

As a result of differing selection pressures due to the differences in physical conditions(example above), both populations will evolve in separate directions to favour their new environment. This will lead to greater and greater genetic differences between the populations over time as a result of changing allele frequencies.

Eventually both populations even if no longer physically isolated will be reproductively isolated. Reproductive isolation is where both populations are no longer able to interbreed to produce fertile offspring, a requirement for an individual species.

Reproductive isolation can occur due to factors such as incompatible genitalia and non overlapping mating seasons. But importantly when two populations can no longer reproduce to produce fertile offspring they are considered two separate species.

Aidan J. A Level Biology tutor, A Level Geography tutor, GCSE Biology...

1 year ago

Answered by Aidan, an A Level Biology tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

118 SUBJECT SPECIALISTS

£20 /hr

Steven A.

Degree: Bioscience (Masters) - Durham University

Subjects offered: Biology, Science+ 5 more

Biology
Science
Maths
Human Biology
English
Chemistry
-Personal Statements-

“Hey! I'm Steven, 18 years old and I'm studying Biochemistry at Durham University. I love tutoring people, to put it simply. At my college i was a tutor to a student in the year below me for chemistry and growing up with a younger sist...”

£20 /hr

Simone V.

Degree: Biochemistry (Bachelors) - University College London University

Subjects offered: Biology, Science+ 4 more

Biology
Science
Maths
French
Dutch
Chemistry

“I believe that the most important thing a tutor can do is to motivate the student and make learning fun! That’s exactly what I want to achieve during a session. At the end of a session, I want you to feel like you learned something in...”

£20 /hr

Odette F.

Degree: Biological Sciences (Bachelors) - Exeter University

Subjects offered: Biology, Geography+ 1 more

Biology
Geography
-Personal Statements-

“ABOUT ME: I am a 2nd Year Biology Student at the University of Exeter. Science as a whole, is a subject I am hugelyenthusiastic about and I would love to share this eagernesswith you! Having spent some of my Gap Year teaching abroad, I...”

About the author

Aidan J.

Currently unavailable: for new students

Degree: Biological Sciences (Bachelors) - Durham University

Subjects offered: Biology, Physics+ 2 more

Biology
Physics
Maths
Geography

“My experience Having regularly tutored a brother with learning difficulties, I have developed the patience to understand and help people of all abilities. Mentoring younger pupils...”

You may also like...

Other A Level Biology questions

What is Exocytosis?

Describe the different roles of aldosterone and cortisol in the body

Name the 5 stages of mitosis in order

The enzyme maltase breaks down maltose to glucose. This takes place at body temperature. Explain why maltase: 1) only breaks down maltose 2) allows this reaction to take place at normal body temperature

View A Level Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok