DIFFERENTLY COLOURED ANIMALSIN PERSPECTIVE

“Endless forms most beautiful”(Darwin/Prof. Sean Carrol)

Differently coloured animals in perspective“Endless forms most beautiful” (Darwin/Prof. Sean Carrol)

PART 1: GENETICBACKGROUND

Where the amino acid can be incor-rectly or inaccurately duplicated/copied = mutation

The variation between organisms is caused by small changes of the DNA molecule during replication, called mutations.

Mutation in DNA occurs at a ‘low’ level in nature, but given the number of replications that take place in germ cells, it is apparent that mutations are commonplace in nature (see later).

Mutations function at the level of the gene and are most frequently small changes that may have no or limited effects on the functioning of the organism (mutations do not cause ‘monsters’, which the loose use of the word ‘mutants’ implies to the uninformed).

Serious mutations involving many base pairs are rare, but when present usually cause anatomical, functional or metabolic problems that affect the health or wellbeing of the animal.

WHAT IS VARIATION/MUTATION?

Mutations in DNA occur at different rates in various parts of the DNA. The frequency of mutations has been scientifically calculated for some traits, and

Areas of mutation vary in different species:

HOW COMMON ARE MUTATIONS?

ESTIMATED MUTATION RATESCharacteristics

Resulting from Gene MutationMutations per

1,000,000 GametesHuman: • Hemophilia • Albinism • Colour blindness

322828

Fruit fly • White eyes • Eyeless • Yellow body colour

2960120

Corn: • Waxy (pollen lacks starch) • Sugary endosperm (seed contains

sugar instead of starch) • Purple kernels

0.012.4

10

Sexual reproduction: Let us look at these numbers another way:

Say there is ONLY 1 inaccurate copy in 1 billion meiotic divisions and duplications.

1 male (man) produces 1 billion sperm cells per day (varies per species)Almost 4 billion men on the earth.

Say, conservatively, that ½ are able to produce sperm and mate:

• = 2 billion men producing 1 billion sperm per day • = 2 000 000 000 x 1 000 000 000 gametes (sperm cells per day) • At 1 inaccurate copy per billion meiotic divisions:

= 2 000 000 000 (2 billion) expected ‘mistakes’ per day in the human population of the world

Rare? No!This is the basis of sex and evolution – without it we would not be here!

BACKGROUND ORIENTATION

Sexual reproduction:

Sexual reproduction is the basis of evolution:

• Because it is not perfect. • Because inaccurate copies occur (mutations/alleles).

Sexual reproduction and mutations are thus the basis of all species and the process of speciation.

Without sexual reproduction, without mistakes in the process, without mutations forming new alleles, none of us would be here in all our glorious difference.

BACKGROUND ORIENTATION

PeopleWhich of us is normal, abnormal, aberrant, a mutant, or a ‘gedroggie’?

THE RESULTS – LOOK AROUND YOU

PeopleWhich of us has no recessive genes?

THE RESULTS – LOOK AROUND YOU

PlantsWe pay more for them and name them after our heroes, e.g. Nelson Mandela

THE RESULTS – LOOK AROUND YOU

BirdsTourists pay a lot and travel thousands of kilometres to see them!

THE RESULTS – LOOK AROUND YOU

VegetablesWe pay more for them AND we eat them!

THE RESULTS – LOOK AROUND YOU

InsectsColour variations are all around us and change to meet the circumstances!

THE RESULTS – LOOK AROUND YOU

Mammals: LionBooks are written on ‘saving the white lion’, differently coloured animals.

THE RESULTS – LOOK AROUND YOU

Mammals: CheetahThousands of people from all over the world visitAnn van Dyk’s De Wildt cheetah sanctuary to see this colour variant.Ann van Dyk has been honoured for her role in preserving the king cheetah.

THE RESULTS – LOOK AROUND YOU

Evolution is dynamic: Climate change is realNo-one knows what precise challenges we will face.Some of today’s alleles, which seem to have no specific advantage/disadvantage, may be the ones that save a species.

THE RESULTS – LOOK AROUND YOU

EFFECTS OF CLIMATE CHANGE ON ECOSYSTEMS/VEGETATIONVegetation under full glacial conditions20 000 - 16 000 14C.

T.E. Steele: Max Planck Institute for Evolutionary Anthropology.Vertebrate Records/Late Pleistocene of Africa (page 3144)2007 Elsevier B.V. All rights reserved

Present potential vegetation

Mammals: Rock pocket miceWhen circumstances change, the ‘abnormal’ become ‘normal’ and SURVIVE.

THE RESULTS – LOOK AROUND YOU

Mammals: Melanistic leopard (Java) and serval (horn of Africa) survive viral epidemics better.The essence of evolution

THE RESULTS – LOOK AROUND YOU

COLOUR VARIANTS IN HISTORYSan paintings

COLOUR VARIANTS IN HISTORY

The golden gemsbuck – 1906

RAAD VAN KURATORE

Richard Dawkins: the ‘tyranny of the discontinuous mind’:

Our ‘boxed’/categorised education rules out the continuum of evolution and speciation.

Definition of a species: can only be logically based on biological criteria = Biological Species Concept (BSC).

Otherwise it is based on opinion or ‘scientific thinking’, with ‘lumpers’ and ‘splitters’ often causing disagreement between scientists.

Evolution is an ever-changing, dynamic, biological process.

Climate change is happening and will drive the process faster and faster.

Fences, roads, urban sprawl prevent natural movement, migration and ‘free sex’. This will create a lack of diversity and decrease the opportunity of a species to survive.

BACKGROUND ORIENTATION

Richard Dawkins: the ‘discontinuous mind’ in The Ancestor’s Tale • Salamander, Ensatina spp. in the Central Valley of California. • European seagulls, (herring gulls and lesser black-backed gulls).

Man-made boxes, e.g. subspecies and normal ranges,ignore the ‘tyranny of the discontinuous mind’.

THE RESULTS – LOOK AROUND YOU

THANK YOU

TO A NEW BIGGER, BRIGHTER AND MORE PRODUCTIVE FUTURE