Giraffes are more amazing than you knew
They’re certainly more amazing than I knew, anyway, and I already knew they were pretty amazing merely by looking at them. It’s the neck, of course—that impossibly long, impossibly stretched-out, Dr. Suess-like neck.
I recently saw surprising footage of giraffes fighting and using their necks as clubs. It wasn’t this exact footage, but it was very similar:
Ouch.
So I had giraffes on the brain when I came across this article describing the latest theories on the genetics of the giraffe’s long neck and cardiovascular idiosyncracies.
I’d never thought about it before, but it makes perfect sense that giraffes would have to have some special way of getting blood all the way up up up to their lofty brains. Sure enough, they do:
The giraffe’s heart, for example, must pump blood two meters straight up in order to provide an ample blood supply to its brain. This feat is possible because the giraffe’s heart has evolved to have an unusually large left ventricle, and the species also has blood pressure that is twice as high as other mammals.
To identify genetic changes likely to be responsible for the giraffe’s unique characteristics, including sprints that can reach 37 miles per hour (60 km/h), Cavener and Agaba compared the gene-coding sequences of the giraffe and the okapi [its nearest relative] to more than forty other mammals…
Using a battery of comparative tests to study the genome sequences of the giraffe and the okapi, the scientists discovered 70 genes that showed multiple signs of adaptations. “These adaptations include unique amino-acid-sequence substitutions that are predicted to alter protein function, protein-sequence divergence, and positive natural selection,” Cavener said. Over half of the 70 genes code for proteins that are known to regulate development and physiology of the skeletal, cardiovascular, and nervous system ”“ just the type of genes predicted to be necessary for driving the development of the giraffe’s unique characteristics.
Among the research team’s discoveries are that several genes known to either to regulate the development of the cardiovascular system or to control blood pressure are among the genes showing multiple signs of adaptation in the giraffe. Some of these genes control both cardiovascular development and skeletal development, suggesting the intriguing possibility that the giraffe’s stature and turbocharged cardiovascular system evolved in concert through changes in a small number of genes.
The article goes on to explain theories of how it might be that the vertebrae of the giraffe (they have the same number of vertebral bones as we have) and their leg bones may have elongated in concert with each other. Fascinating.
There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.
That’s proba bly from that fantastic series on Africa.
I never paid much attention to giraffes, but my grandmother always liked them, so back in 2007, I decided to make a giraffe out of Sculpey for her.
After several false starts I ended up just doing a “bust” and it was through studying lots of photos I came to realize just how weird they look.
https://www.flickr.com/photos/conceptjunkie/566972860/in/album-72157601069477190/
https://www.flickr.com/photos/conceptjunkie/566972898/in/album-72157601069477190/
To me, the side view looks really wrong, but it wasn’t, based on the photos I studied. Giraffes are weird and fascinating.
Amazing creatures. Many years ago a giraffe was born at the National Zoo in DC. If you think that adults are ungainly.
Giraffes are almost immune to lion attack.
Only one has ever been recorded — and that was by an amateur. The victim was not an adult, just a ‘teen.’
The pros have been looking to film such an attack — for seventy-years.
The giraffe also has an astounding tongue. It’s prehensile.
I read somewhere (Real Clear Science?) today a piece about Mendel having distorted the science taught today by directing all the attention to the genes while ignoring other factors. I though it was the dumbest piece I had ever read. Of course genes and gene expression can be affected by other factors, but without knowing that genes exist, it would be impossible to tell the role of other factors. If you think about all the information we have learned since the human genome project pushed new sequencing techniques and how the cloud has made it possible to compare sequences from E. coli with every new bacterium pulled up from the bottom of the sea, it is just amazing. Why do people not know that lots of basic research that is conducted might not pay off for years or decades, but eventually it will fit into the enormous puzzle that is life.
“their leg bones may have elongated in concert with each other. Fascinating.” neo
It certainly is fascinating and I for one had no idea that, that is how male giraffes fight.
FWIW, in 1982, I noticed a nearby, extremely tall man start to walk across the street. I immediately recognized the LA basketball player Kareem Abdul-Jabbar, who stood 7′-1″ & 7/8th w/o shoes… but it wasn’t until he walked up to his full size Mercedes Benz that his height and particularly long legs became clear to me. His waist belt lined up perfectly with the roof top of the Benz…
Years later, I held a signed Shaquille O’Neal basketball shoe. Laid against my forearm, it stretched exactly from my elbow to the very tip of my longest finger… that btw measures exactly 18.5 inches.
I ve always been fascinated by giraffes, & always looked for them when buying animals motifs for my youngsters. Along with lions & monkeys they are frequently depicted in *stuff* for kids. In additional to their cerebral perfusion being such a fine tuned mechanism, the opposite is true as well. When they put their head down to drink the rush of blood must be slowed ever so perfectly so the animal dosent have a stroke !
Giraffes are easier to make using the theory of genetics which has modification of the genome within a single generation. That way you don’t have to rely on mechanics to create new species from different species, or mutations that jump start from one physical type to another.
A graduation change between generations, within the same generation, is feasible and is a better explanation of how genes control and are controlled by the biological interface.
When you see the Acacia trees that are so abundant in the game areas in Africa, you can get a visual of why giraffes may have developed the way they did. They love the leaves of the Acacias, which grow in a parasol shape. To reach the leaves on enough trees they needed to get taller. That’s probably all wrong, but it was the first thing that I thought of when I saw the way Acacia trees grow and learned that the Acacia leaves are their favorite food.
I got to feed a giraffe at a game park and was amazed by its tongue.Their tongue is prehensile so that they can get at the leaves, but avoid the sharp thorns with which the Acacia is well endowed.
One of the most gorgeous sights I have ever seen was a line of giraffes on a ridge, silhouetted against a setting sun. Such stately creatures! Took my breath away.
Giraffes are a great example of evolution. They are eloquent and fascinating.
ConceptJunkie, your Grandma must have loved her gift. You did a wonderful job. Thanks for sharing.
Love the giraffe sculpture, ConceptJunkie! Captures the weirdness and beauty. You have a lucky grandmother.
This is one of the mysteries of evolution that all mammalians without exception have the same number of neck vertebrae, namely seven. Giraffe with its long neck has the same number of these as a pig, hardly having neck at all! That means that there is no a single gene or genetic net responsible for this trait – number of neck vertebrae – while in reptiles no such restriction exist. This should give a pause to those who believe that every trait has a genetic background behind it, or that a purely genetic theory of evolution (like Neodarwinism) is even theoretically possible. So the only way to have a very long neck is the elongation of vertebrae, which also makes other bones elongated, since their development uses the same genetic net.
Giraffes are amazing. All the language in the article about “evolved” and “adapted” is just an unnecessary gloss on the wonderful facts of their design.
Psalm 104
1 Let all that I am praise the Lord.
O Lord my God, how great you are!
You are robed with honor and majesty.
2 You are dressed in a robe of light.
You stretch out the starry curtain of the heavens;
3 you lay out the rafters of your home in the rain clouds.
You make the clouds your chariot;
you ride upon the wings of the wind.
4 The winds are your messengers;
flames of fire are your servants.
5 You placed the world on its foundation
so it would never be moved.
6 You clothed the earth with floods of water,
water that covered even the mountains.
7 At your command, the water fled;
at the sound of your thunder, it hurried away.
8 Mountains rose and valleys sank
to the levels you decreed.
9 Then you set a firm boundary for the seas,
so they would never again cover the earth.
10 You make springs pour water into the ravines,
so streams gush down from the mountains.
11 They provide water for all the animals,
and the wild asses quench their thirst.
12 The birds nest beside the streams
and sing among the branches of the trees.
13 You send rain on the mountains from your heavenly home,
and you fill the earth with the fruit of your labor.
14 You cause grass to grow for the livestock
and plants for people to use.
You allow them to produce food from the earth–
15 wine to make them glad,
olive oil to soothe their skin,
and bread to give them strength.
16 The trees of the Lord are well cared for–
the cedars of Lebanon that He planted.
17 There the birds make their nests,
and the storks make their homes in the cypresses.
18 High in the mountains live the wild goats,
and the rocks form a refuge for the hyraxes.[b]
19 You made the moon to mark the seasons,
and the sun knows when to set.
20 You send the darkness, and it becomes night,
when all the forest animals prowl about.
21 Then the young lions roar for their prey,
stalking the food provided by God.
22 At dawn they slink back
into their dens to rest.
23 Then people go off to their work,
where they labor until evening.
24 O Lord, what a variety of things you have made!
In wisdom you have made them all.
The earth is full of your creatures.
25 Here is the ocean, vast and wide,
teeming with life of every kind,
both large and small.
26 See the ships sailing along,
and Leviathan,[c] which you made to play in the sea.
27 They all depend on you
to give them food as they need it.
28 When you supply it, they gather it.
You open your hand to feed them,
and they are richly satisfied.
29 But if you turn away from them, they panic.
When you take away their breath,
they die and turn again to dust.
30 When you give them your breath,[d] life is created,
and you renew the face of the earth.
31 May the glory of the Lord continue forever!
The Lord takes pleasure in all he has made!
32 The earth trembles at his glance;
the mountains smoke at his touch.
33 I will sing to the Lord as long as I live.
I will praise my God to my last breath!
34 May all my thoughts be pleasing to him,
for I rejoice in the Lord.
35 Let all sinners vanish from the face of the earth;
let the wicked disappear forever.
Let all that I am praise the Lord.
Praise the Lord!
This book is exceptional regarding biology, physics, and evolution.
Life’s Devices: The Physical World of Animals and Plants (Princeton Paperbacks)
It is not written on the graduate level, and is understandable and enjoyable for non-biologists IMO.
I’ll have to check and see if the author addresses many of the wonders of giraffe physiology and biomechanics.