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Feedback archive →
Feedback 2007
Sheep and goats? Since when?
Image Wikipedia
Goat evolution? Some populations of goats thrive on particular
leaves that are toxic to other goats. This used to be attributed to evolution, with
the leaf-eating goats being said to have evolved their ability to eat the leaves.
This was disproved by the brilliant creationist agricultural scientist Dr Raymond
Jones, who surmised that the ability was due not to evolution but to helpful gut
bacteria. Sure enough, ordinary goats dosed with bacteria-laden stomach fluid from
the ‘evolved’ goats were suddenly able to consume the leaves without
becoming sick—see The Luecaena story.
This week’s feedback comes from Raymond W of London, United Kingdom, who has
some questions relating to an article he read in the latest issue of Creation
magazine. Andrew Lamb replies.
Dear Sir,
I am currently researching the origin of both wild and domestic goats from a Biblical
perspective, and was very interested in your article entitled ‘Separating
the sheep from the goats’ [Creation
29(3):43–45]. From a reading of this article,
I would be very grateful if you would answer the following questions for me:
1. Were sheep and goats one kind prior to the Flood, and thus speciation took place
post-Flood? Or were there sheep and goats pre-Flood?
2. Did domestication take place pre-Flood or post-Flood?
3. It is universally assumed that the ancestor of the domestic goat is the Bezoar
(Capra aegagrus), but is it possible that the origin of the domestic form
came at a time before distinct speciation had taken place?
With thanks, Raymond W.
Dear Raymond
Thank you for your email.
I am currently researching the origin of both wild and domestic goats from a Biblical
perspective,
The field of study concerned with identifying the original kinds is known as baraminology,
from the Hebrew term for biological kind, baramin. The biblical kind often
equates to the family level in the modern biological classification scheme, and
sometimes to genus or order. Some excellent baraminology papers have appeared in
recent issues of Journal of Creation, including one on the sheep-goat kind1 by Dr
Jean Lightner, who was also the author of our Creation magazine
article on sheep and goats.
But first, for our readers, just what is the difference between a sheep and a goat?
The following extract from an encyclopedia discusses some of the differences between
goats and sheep:
Image Wikipedia
There is wide variation in hornage and pelage (wool/hair)
amongst the tsōn kind. You can get varieties with no horns (i.e. polled),
two horns, four horns (e.g. Manx sheep—pictured) and even
six horns (e.g. some Jacob sheep). You can get species with beards, species with
manes (e.g. the Barbary sheep), and even varieties with bald patches (see
No flies on ‘freak’ sheep).
Though closely related to sheep, to the point of causing occasional taxonomic confusion,
goat behaviour is quite different. Sheep are primarily roaming grazers which travel
in herds (also known as flocks), while goats are browsers like deer, eating branches
and twigs, and tend to be more territorial. Like sheep, though, they have horns
that continue to grow throughout their lifetime instead of antlers that fall off
once a year. Unlike sheep, both male and female goats grow horns, and both sexes
can have beards. Goats are herd animals and survive better in a herd situation than
alone. But they tend to be more aggressive with predators, and some sheep herders
will run a few goats with the herd because after initially fleeing, the goats will
stand up to a predator and possibly deter them, whereas sheep will continue to run.
A herd typically has a Herd Queen, who leads the herd while browsing. They are also
much more lively than sheep and their inquisitive nature makes them curious pets.
Sheep and goats have the same horizontal slit pupil in their eyeballs. Sheep tails
go down, which is why they are sometimes docked, whereas goat tails go up.2
Importantly, sheep and goats differ in the number of chromosomes. Goats have 60
chromosomes while domestic sheep have 54 chromosomes. Despite this, hybrid offspring
can be produced, having 57 chromosomes—see
sheep-goat hybrid for an example. However, fertile sheep-goat hybrids
are extremely rare.
Fertile hybrids are not unusual in all animal kinds. Consider the Equus
(horse) kind. Domestic horses have 64 chromosomes while Przewalski’s horses
have 66, but they can produce fertile offspring—see
Resurrecting a prehistoric horse. Donkeys have 62 chromosomes, but occasionally
fertile mules (donkey–horse crosses) are produced—see
Mule gives birth. Zebras have only 44 chromosomes, but they readily hybridize
with horses (66 chromosomes)—see
Shetland-Zebra hybrid.
1. Were sheep and goats one kind prior to the Flood, and thus speciation took place
post-Flood? Or were there sheep and goats pre-Flood?
…in the pre-Flood world animals may not have feared people, in which case
domestication, in the sense of taming wild animals, may not have been an issue…
For two reasons, we think the speciation into sheep and goats probably took place
after the Flood. Firstly, a Hebrew word whose meaning encompasses both sheep and
goats (tsōn) is used in the pre-Flood chapters of Genesis, as explained
in the Creation article:
It is interesting to note that in Hebrew, the language in which much of the Bible
was originally written, there is a word that refers to sheep and/or goats. This
word is used in Genesis to describe the animals that Abel, a son of Adam and Eve,
raised and used as a sacrifice to God (Genesis 4:2,4). The Bible commonly refers to sheep and goats
collectively. The frequent use of a single word to refer to sheep and goats also
strongly suggests that these animals belong to the same created kind. However, there
are also words that specifically refer to sheep and others that specifically refer
to goats.3
Secondly, as the article goes on to explain, one of the characteristics that distinguishes
sheep from goats is that sheep have no guard hairs, only underfur (wool). If the
individual specimens on the Ark had been sheep that had lost the genetic information
for guard hairs, then it would be difficult for strains of goats, which do
have guard hairs, to arise subsequently, as this would require the regaining of
lost information.
2. Did domestication take place pre-Flood or post-Flood?
Pre-Flood people certainly kept livestock, though this may not have involved a need
to tame them. Besides Abel, mentioned previously, who kept a flock to provide animals
suitable for sacrifice, there was also Jabal and his clan (Genesis 4:20) who kept livestock.
After the Flood, God gave Noah and his family (and by extension all mankind) permission
to eat animals, while simultaneously advising them that the animals would fear them
(Genesis 9:2-3). This could suggest that in the pre-Flood
world animals may not have feared people, in which case domestication, in the sense
of taming wild animals, may not have been an issue in the way that it is in the
post-Flood world.
Collectively they would convey to the post-Flood world a comprehensive
range of the genetic variety for their kind.
Noah and his family would not have eaten meat in pre-Flood times, since God had
designated plants to be mankind’s food (Genesis 1:29) and Noah was a blameless man (Genesis 6:9) who did what God commanded (Genesis 7:5). Apparently it was no longer possible
after the Flood for people to easily get all the nourishment they needed from plants
alone, hence God’s explicit permission to eat flesh.
It seems likely that pre-Flood people would have deliberately bred their animals
to enhance useful traits. Abel selected the best of his flock for sacrifice to God,
and it is reasonable to suppose that he would select the best of his flock for breeding
as well. And Jabal and his clan, besides keeping livestock, also lived in tents.
They could conceivably have developed woolly/furry/hairy animal breeds to facilitate
the making of cloth or felt for tents. In Central Asian countries today, there are
people who live in
tents made from wool felt. Of course animal skins or plant fibres could
also have been used. In fact, just why was Jabal keeping cattle? He was
not from the godly line of patriarchs that led to Noah, but from the rebellious
and largely wicked line of Cain, so sacrifice to God doesn’t seem a likely
motive. Henry Morris gives some pertinent comments:
The term “cattle” here [Genesis 4:20] includes camels and asses (Exodus 9:3) as well as kine, goats, and perhaps others.
Possibly this suggests that his [Jabal’s]contemporaries were acquiring the
habit of eating meat as well as fruit and herbs, and thus had disobeyed still another
of God’s primal commands (Genesis 1:29). Or perhaps it means simply that he was producing
them commercially for other purposes: beasts of burden, milk, skins for clothing,
and so forth.4
So, deliberate breeding of varieties of tsōn lacking guard hairs could
potentially have already given rise to sheep and goat varieties before the Flood.
Sheep and goats are clean animals (as later codified under the Levitical law), so
there would have been seven of the tsōn kind taken aboard the Ark.
Those seven individuals could have been ‘pluripotent’ non-specialized
tsōn specimens, each still containing a comprehensive range of the
genetic information for their kind. Or alternatively, perhaps there could have been
both sheep and goats, and even other varieties, among those seven tsōn
on the Ark. Individually, they would each provide just a distinct subset of tsōn
genes, but collectively they would convey to the post-Flood world a comprehensive
range of the genetic variety for their kind.
3. It is universally assumed that the ancestor of the domestic goat is the Bezoar
(Capra aegagrus), but is it possible that the origin of the domestic form
came at a time before distinct speciation had taken place?
Image sxc.hu
A bezoar
Whichever species of goat or sheep today is the most genetically robust, having
retained the greatest range of the created genetic variety originally present within
its kind, would be the species that we would consider closest to the ancestral kind.
For the tsōn kind, this may well be the wild goat (Capra aegagrus).
Not all populations of wild goat are referred to as bezoars. The bezoar is defined
as a ‘wild goat with flat scimitar-shaped horns’
5 and it belongs to the main goat genus, Capra.
There are both ancient6
and modern7 records of bezoar-domestic
goat hybrids.
We do not know the exact limits/range of the tsōn kind, but it probably
encompasses animals from several other genera besides Ovis (the main sheep
genus) and Capra, potentially including animals such as the
serow,
goral,
tahr,
chamois,
bharal, and
takin. Most of these animals look pretty much like goats
or sheep, though some look a bit antelopish. See Dr Lightner’s Journal of
Creation paper for a comprehensive discussion of the issue of the range
of the sheep-goat kind, and a table of hybrids recorded in the academic literature.
Image Wikipedia
The ancient Mesopotamian cuneiform tablet EC.74.3 records
a transaction involving ‘one mouflon-hybrid ewe, one bezoar-hybrid goat, and
one female bezoar-hybrid kid’.6 It is dated
to around 2000 BC. (The tablet pictured here is
not EC.74.3.)
More and more animal genomes are being sequenced, and new techniques in gene sequencing
are leading to rapid progress. With respect to the human genome, enough sequencing
has been done that it is already becoming possible to trace a person’s genealogy
through gene-mapping (see Human genetic diseases box
below). Similarly, as more sequencing is done on the various sheep and goat species,
it may become possible to re-trace tsōn speciation events. With sufficient
genetic testing, it may one day be possible to determine the exact sequence of speciation
among the various descendant populations. It will also become more apparent which
similar-looking species are indeed related, and which are separated by unbridgeable
genomic differences, descendants of different original kinds. Study of the genomes
of tsōn species will also indicate which are likely the most genetically
depleted/degenerate, and which are the most genetically robust, and hence closest
to the original created tsōn kind.
However, in answer to your specific question, domestic goats (Capra aegagrus hircus)
are classified not as a separate species, but merely as a subspecies of
the wild goat (Capra aegagrus), so it seems distinct speciation has not
taken place between these two daughter populations of the tsōn kind.
With thanks, Raymond W.
With pleasure
Andrew Lamb
Information Officer
Human genetic diseases
Every person on earth carries in their genome their own personal set of hundreds
of genetic defects, and these defects accumulate from one generation to the next
as new defects are incurred. This phenomenon is known as ‘mutational load’.
DNA molecules are very large and fairly unstable. Radiation and contact with water
and other chemicals are continually causing chemical ‘letters’ on the
DNA strands to become unreadable. Besides straightforward damage like this, DNA
can also incur copying errors such as deletions and insertions during mitosis (cell
division).
Countering this, living cells have an incredible array of specialised machinery
devoted to detecting and rectifying any such errors, and continually in operation
throughout the cell’s lifetime. There are hundreds of enzymes that go up and
down the DNA, comparing the two strands and replacing any damaged base pairs. However,
despite all this, errors do occasionally escape detection and repair and become
fixed in the DNA. And if a mutation becomes fixed in a sperm or ovum cell, then
there is the possibility of that mutation being passed on to the next generation.
Every single one of us has a few more mutations than our parents had, and so each
person’s own unique set of defects thus constitutes a complete history of
their ancestry back to Noah’s family.
Many genetic diseases can be traced back through parents, grandparents, etc., to
the person who incurred the original mutation causing the disease. For example one
strain of the genetically inherited disease haemophilia can be traced back to Queen
Victoria.8 A ‘werewolf’
mutation causing excessive hairiness can be traced back to a particular Mexican
individual—see The
werewolf gene. And some Western Australian aborigines and American Amish
people share a rare six-finger mutation which can be traced back to a common Dutch
ancestor—see
Aborigines and Amish link. (Dutch sailors marooned on the west coast of
Australia in the 1600’s are thought to be the source of certain European genetic,
cultural, and linguistic traits in some Western Australian Aboriginal tribes.9)
Many genetic diseases originated so long ago in history that they are now very widespread,
and the individual person who first incurred the mutation causing the disease can
no longer be identified. For example the globally widespread ability of adults to
digest lactose in milk may be due to a mutation that occurred very long ago.10
Most genetic diseases can be caused by more than one specific mutation. For example,
to date there are 130 different recorded mutations of the CFTR gene on human chromosome
7 that result in the disease cystic fibrosis. Six other mutations of this gene have
been identified that cause other diseases, such as ‘congenital bilateral aplasia
of the vas deferens’.11
All this is very consistent with the biblical account of post-Fall degeneration
from an original ‘very good’ (Genesis 1:31) state.
DNA sequencing potentially provides the means to compile complete genetic lineages
for the entire human race, and several efforts to do just that are already underway,
for example
The DNA Ancestry Project and The Genographic Project. For some biblical applications
of this type of research, see the articles on ‘Y-chromosome Adam’ and
‘Mitochondrial Eve’ in Q&A: Genetics.
References
- Jean Lightner, Identification
of species within the sheep-goat kind (Tsoan monobaramin), Journal of Creation
20:61–65, 2006. Return to Text.
- Wikipedia, Capra (genus): Similarity to sheep, <http://en.wikipedia.org/wiki/Capra_(genus)#Similarity_to_sheep>,
11 July 2007. Return to Text.
- Jean Lightner, Separating
the sheep from the goats, Creation 29:43–45; 43.
Return to Text.
- Henry Morris,
The Genesis Record, page 146. Return to Text.
- The New Oxford Dictionary of English, Clarendon Press,
1998, page 168. Return to Text.
- Tablet EC.74.3,
http://www.ripon.edu/academics/
art/clark/CUNEIFORM.HTML, 27 July 2007. ‘EC’ stands for Edward Clark,
the finder of the tablet. Return to Text.
-
http://www.huntingenthusiast.net/viewtopic.php?p=1155#280, 27 July 2007.
Return to Text.
- Queen Victoria was a carrier of the disease. Being a carrier
means that her DNA had the mutation, but it was not expressed. The mutation responsible
probably originally occurred in the sperm from her aging father which fertilised
the ovum from her mother from which she grew. Family, Life and Health Encyclopedia,
volume 12, pages 1662, 1665, Marshall Cavendish 1970. Return to Text.
- The secular book And Their Ghosts May Be Heard by
Rupert Gerritsen details such claims. Return to Text.
- Ann Gibbons, Milk Tolerance Evolved More Than Once, Science
NOW Daily News, 11 December 2006. Return to Text
- <http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=602421>,
27 July 2007. Return to Text.
Published: 1 August 2007(GMT+10)
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