Ants, Wildebeest, Penguins, and More: A Zoo of Animal Designs
Let’s take a varied look at animals from large to small that arouse wonder at the amazing designs built into them.
When you consider migrating birds, flyers usually come to our minds, not swimmers. The Fiordland crested penguins of New Zealand, though, swim an Ironman (or is that Ironbird) match each year in a record-setting migration. Science Daily tells how Thomas Mattern and team from the University of Otago attached satellite transmitters to 17 birds to watch, for the first time, where they go at sea.
They found that the penguins travelled between 3,500 and 6,800 km on their 69-day migration — making theirs one of the longest penguin pre-moult migrations recorded to date. The birds travelled between 20km and 80km per day — which the authors suggest may be close to the upper limit for penguin swimming. [Emphasis added.]
Their paper in PLOS ONE calls the swim champs “Marathon penguins” for this achievement. Also known as Tawaki, they are among the rarest penguin species and the only ones who nest on New Zealand — and in addition, the only penguins who nest in a tropical rainforest environment. Their paired yellow head crests give them “a ‘rockstar’ appearance and comic antics,” an article says on NewZealand.com, making them “among New Zealand’s most endearing wildlife.”
Wild Muscle-beasts: Wildebeest
Don’t kick sand in the face of a wildebeest by joking that it looks like it was made by a committee. It might flex its muscles and charge. Curtis et al., publishing in Nature, tell about “Remarkable muscles, remarkable locomotion in desert-dwelling wildebeest.”
To move about in a dry environment where water might be undependable, large mammals have to balance energy utilization with heat production. This is the “cost of transport” (COT) which is highest for animals that walk on land instead of fly or swim. Wildebeest are well equipped to pay it. They put other animals their size and smaller to shame when it comes to energy efficiency:
Here we used GPS-tracking collars with movement and environmental sensors to show that blue wildebeest (Connochaetes taurinus, 220 kg) that live in a hot arid environment in Northern Botswana walked up to 80 km over five days without drinking. They predominantly travelled during the day and locomotion appeared to be unaffected by temperature and humidity, although some behavioural thermoregulation was apparent. We measured power and efficiency of work production (mechanical work and heat production) during cyclic contractions of intact muscle biopsies from the forelimb flexor carpi ulnaris of wildebeest and domestic cows (Bos taurus, 760 kg), a comparable but relatively sedentary ruminant. The energetic costs of isometric contraction (activation and force generation) in wildebeest and cows were similar to published values for smaller mammals. Wildebeest muscle was substantially more efficient (62.6%) than the same muscle from much larger cows (41.8%) and comparable measurements that were obtained from smaller mammals (mouse (34%) and rabbit (27%)).
The research team determined that the clumsy-looking animals would put bodybuilders to shame in the gym:
In summary, wildebeest, although not considered extreme arid environment specialists, can undertake long journeys in the absence of water in hot dry conditions and frequently spend three and occasionally up to five days without drinking. This requires them to have a low COT [cost of transport], which is likely to be delivered, in part, by muscles that are specialized at the level of the cross-bridge to deliver more mechanical work and release less heat from each ATP molecule split than any mammalian muscle studied to date.
Self-Repair Champ on the Seashore
From muscly to limp, we consider the limpet. These little shell-building mollusks have an ability that rivals its counterpart in mammals. Science Daily explains:
New research from bioengineers paints a surprisingly complex picture of limpets — the little seashore creatures that are ubiquitous on rocky patches of beaches in many parts of the world. The bioengineers have discovered that limpets are able to detect minor damage to their shells with surprising accuracy before remodelling them to make them stronger. In many ways, the way they heal is similar to the way broken bones mend in mammals.
The paper by O’Neill et al. in the Journal of the Royal Society Interface uses that word “remarkable” again of the lowly limpet, Patella vulgata. Even after intentionally damaging shells of limpets, reducing their strength 50 to 70 percent, the creatures were able to repair their shells within 60 days to “statistically indistinguishable” strength of control shells. “This work has demonstrated the remarkable ability of limpets to detect the mechanical weakening of their shells caused by relatively subtle forms of damage and to take appropriate action to restore shell strength.”
Tiny Celestial Navigators
How can navigation equipment fit into a fruit-fly brain? In Current Biology’s recent special on migration (see here), one paper stands out: Giraldo et al.’s revelation that the itsy bitsy fruit fly can navigate for miles and remember its route from one flight to the next. How does it do it? As with the limpet, watch for a comparison to mammalian abilities:
Despite their small brains, insects can navigate over long distances by orienting using visual landmarks , skylight polarization, and sun position. Although Drosophila are not generally renowned for their navigational abilities, mark-and-recapture experiments in Death Valley revealed that they can fly nearly 15 km in a single evening. To accomplish such feats on available energy reserves, flies would have to maintain relatively straight headings, relying on celestial cues. Cues such as sun position and polarized light are likely integrated throughout the sensory-motor pathway, including the highly conserved central complex. Recently, a group of Drosophila central complex cells (E-PG neurons) have been shown to function as an internal compass, similar to mammalian head-direction cells.
An Ant Never Forgets
Speaking of abilities packed into small brains, ants can learn up to 14 food odors and remember them for their whole lives. The Max Planck Institute praises an “amazing ability” in the desert ant:
The desert ant Cataglyphis fortis has amazing abilities to trace food and to return to its nest in the North African desert. Its sense of smell has a central function for orientation. The ant is not only a master navigator, it is also a memory artist.
This memory ability exceeds the requirements of survival:
“We were amazed how quickly the ants learned food-associated odors and how long they could remember them. Even ants, that had learned an odor more than 25 days ago, were able to remember it.” In nature, most ants have a short life and are usually killed by a predator within six days. Therefore it is particularly astonishing that ants that have reached more than four times the average age could still remember what they had learned.
The researchers, publishing in PNAS, were puzzled about why the ants seemed to learn and remember external food odors more easily than nest odors. They reasoned that “These different memory characteristics make sense, as food is unpredictable and ants might experience many different food items in consecutive foraging runs, while the nest odor will not dramatically change during an ant’s lifetime.”
The Darwinian picture of evolving life expects the smallest, earliest animals to be the simplest. These cases illustrate, though, that “primitive” organisms often have astonishing capabilities that rival those of more “evolved” animals like mammals. In a design paradigm, this makes sense. Design modules such as navigation or repair can be simplified and miniaturized downwards for the needs of small animals, like fruit flies, ants and limpets, using similar algorithms, whereas large animals, like the wildebeest, have more brain space for the full package.
Winston Ewert’s paper on dependency graphs (explained on ID the Future here and here) shows that this is exactly how programmers use modules that generate nested hierarchies like those seen in biology. The signal of dependency graphs, he also shows, fits biological data enormously better than Darwin’s tree diagram. That’s why finding celestial navigation in birds and in fruit flies makes sense, and why finding material repair in limpets and in human bones makes sense. The exact opposite of sense, in fact, is the “sheer dumb luck” Darwinism depends on to create the mere “appearance of design.” Ants, wildebeest, penguins, and all the animals in the zoo testify that design is real.
Photo: Blue Wildebeest (Connochaetes taurinus), by Muhammad Mahdi Karim [GFDL 1.2], from Wikimedia Commons.