What do these animals have in common?
More than you might think.
Along with over 5,000 other species, they're mammals, or members of class mammalia.
All mammals are vertebrates, meaning they have backbones.
But mammals are distinguished from other vertebrates by a number of shared features.
That includes warm blood, body hair or fur, the ability to breathe using lungs, and nourishing their young with milk.
But despite these similarities, these creatures also have many biological differences, and one of the most remarkable is how they give birth.
Let's start with the most familiar, placental mammals.
This group includes humans, cats, dogs, giraffes, and even the blue whale, the biggest animal on Earth.
Its placenta, a solid disk of blood-rich tissue, attaches to the wall of the uterus to support the developing embryo.
The placenta is what keeps the calf alive during pregnancy.
Directly connected to the mother's blood supply, it funnels nutrients and oxygen straight into the calf's body via the umbilical cord, and also exports its waste.
Placental mammals can spend far longer inside the womb than other mammals.
Baby blue whales, for instance, spend almost a full year inside their mother.
The placenta keeps the calf alive right up until its birth, when the umbilical cord breaks and the newborn's own respiratory, circulatory, and waste disposal systems take over.
Measuring about 23 feet, a newborn calf is already able to swim.
It will spend the next six months drinking 225 liters of its mothers thick, fatty milk per day.
Meanwhile, in Australia, you can find a second type of mammal - marsupials.
Marsupial babies are so tiny and delicate when they're born that they must continue developing in the mother's pouch.
Take the quoll, one of the world's smallest marsupials, which weighs only 18 milligrams at birth, the equivalent of about 30 sugar grains.
The kangaroo, another marsupial, gives birth to a single jelly bean-sized baby at a time.
The baby crawls down the middle of the mother's three vaginas, then must climb up to the pouch, where she spends the next 6-11 months suckling.
Even after the baby kangaroo leaves this warm haven, she'll return to suckle milk.
Sometimes, she's just one of three babies her mother is caring for.
A female kangaroo can often simultaneously support one inside her uterus and another in her pouch.
In unfavorable conditions, female kangaroos can pause their pregnancies.
When that happens, she's able to produce two different kinds of milk, one for her newborn, and one for her older joey.
The word mammalia means of the breast, which is a bit of a misnomer because while kangaroos do produce milk from nipples in their pouches, they don't actually have breasts.
Nor do monotremes, the third and arguably strangest example of mammalian birth.
There were once hundreds of monotreme species, but there are only five left: four species of echidnas and the duck-billed platypus.
The name monotreme means one hole referring to the single orifice they use for reproduction, excretion, and egg-laying.
Like birds, reptiles, fish, dinosaurs, and others, these species lay eggs instead of giving birth to live young.
Their eggs are soft-shelled, and when their babies hatch, they suckle milk from pores on their mother's body until they're large enough to feed themselves.
Despite laying eggs and other adaptations that we associate more with non-mammals, like the duck-bill platypus's webbed feet, bill, and the venomous spur males have on their feet, they are, in fact, mammals.
That's because they share the defining characteristics of mammalia and are evolutionarily linked to the rest of the class.
Whether placental, marsupial, or monotreme, each of these creatures and its unique birthing methods, however bizarre, have succeeded for many millennia in bringing new life and diversity into the mammal kingdom.
The school of architecture that I studied at some 30 years ago happened to be across the street from the wonderful art gallery designed by the great architect Louis Kahn.
I love the building, and I used to visit it quite often.
One day, I saw the security guard run his hand across the concrete wall.
And it was the way he did it, the expression on his face -- something touched me.
I could see that the security guard was moved by the building and that architecture has that capacity to move you.
I could see it, and I remember thinking, "Wow.
How does architecture do that?"
At school, I was learning to design, but here -- here was a reaction of the heart.
And it touched me to the core.
You know, you aspire for beauty, for sensuousness, for atmosphere, the emotional response.
That's the realm of the ineffable and the immeasurable.
And that's what you live for: a chance to try.
So in 2003, there was an open call for designs for the Bahá'í Temple for South America.
This was the first temple in all of South America.
It's a continental temple, a hugely important milestone for the Bahá'í community, because this would be the last of the continental temples and would open the door for national and local temples to be built around the world.
And the brief was deceptively simple and unique in the annals of religion: a circular room, nine sides, nine entrances, nine paths, allowing you to come to the temple from all directions, nine symbolizing completeness, perfection.
No pulpit, no sermons, as there are no clergy in the Bahá'í faith.
And in a world which is putting up walls, the design needed to express in form the very opposite.
It had to be open, welcoming to people of all faiths, walks of life, backgrounds, or no faith at all; a new form of sacred space with no pattern or models to draw from.
It was like designing one of the first churches for Christianity or one of the first mosques for Islam.
So we live in a secular world.
How do you design sacred space today?
And how do you even define what's sacred today?
I stumbled across this beautiful quote from the Bahá'í writings, and it speaks to prayer.
It says that if you reach out in prayer, and if your prayer is answered -- which is already very interesting -- that the pillars of your heart will become ashine.
And I loved this idea of the inner and the outer, like when you see someone and you say, "That person is radiant."
And I was thinking, "My gosh, how could we make something architectural out of that, where you create a building and it becomes alive with light?
Like alabaster, if you kiss it with light, it becomes alive.
And I drew this sketch, something with two layers, translucent with structure in between capturing light.
Maybe a pure form, a single form of emanation that you could imagine would be all dome and everything we kept making was looking too much like an egg.
(Laughter) A blob.
So you search.
You all know this crazy search, letting the process take you, and you live for the surprises.
And I remember quite by accident I saw this little video of a plant moving in light, and it made me think of movement, reach, this idea that the temple could have reach, like this reach for the divine.
You can imagine also that movement within a circle could mean movement and stillness, like the cosmos, something you see in many places.
(Laughter) But rotation was not enough, because we needed a form.
In the Bahá'í writings, it talks about the temples being as perfect as is humanly possible, and we kept thinking, well, what is perfection?
And I remember I stumbled into this image of this Japanese basket and thinking our Western notions of perfection need to be challenged, that this wonderful silhouette of this basket, this wonkiness, and that it has the kind of dimple of what you might imagine a shoulder or the cheekbone, and that kind of organic form.
And so we drew and made models, these lines that merge at the top, soft lines, which became like drapery and translucent veils and folding, and the idea of not only folding but torquing -- you remember the plant and the way it was reaching.
And this started to become an interesting form, carving the base, making the entrances.
And then we ended up with this.
This is this temple with two layers, nine luminous veils, embodied light, soft-flowing lines like luminescent drapery.
180 submissions were received from 80 countries, and this was selected.
So we went to the next stage of how to build it.
We had submitted alabaster.
But alabaster was too soft, and we were experimenting, many experiments with materials, trying to think how we could have this kind of shimmer, and we ended up with borosilicate.
And borosilicate glass, as you know, is very strong, and if you break borosilicate rods just so and melt them at just the right temperature, we ended up with this new material, this new cast glass which took us about two years to make.
And it had this quality that we loved, this idea of the embodied light, but on the inside, we wanted something with a soft light, like the inner lining of a jacket.
On the outside you have protection, but on the inside you touch it.
So we found this tiny vein in a huge quarry in Portugal with this beautiful stone, which the owner had kept for seven generations in his family, waiting for the right project, if you can believe it.
Look at this material, it's beautiful.
And the way it lights up; it has that translucent quality.
So here you see the structure.
It lets the light through.
And looking down, the nine wings are bound, structurally but symbolically strong, a great symbol of unity: pure geometry, a perfect circle, 30 meters in section and in plan, perfectly symmetrical, like the idea of sacredness and geometry.
And here you see the building going up, 2,000 steel nodes, 9,000 pieces of steel, 7,800 stone pieces, 10,000 cast glass pieces, all individual shapes, the entire superstructure all described, engineered, fabricated with aerospace technology, prefabricated machine to machine, robotically, a huge team effort, you can imagine, of literally hundreds, and within three percent of our $30 million budget set in 2006.
(Applause) Nine wings bound together forming a nine-pointed star, and the star shape moving in space, tracking the sun.
So here it is.
Audience: Wow!
(Applause) Hopefully, a befitting response to that beautiful quote, "a prayer answered," open in all directions, capturing the blue light of dawn, tent-like white light of day, the gold light of the afternoon, and of course, at night, the reversal: sensuous, catching the light in all kinds of mysterious ways.
And the site: it's interesting; 14 years ago when we made the submission, we showed the temple set against the Andes.
We didn't have the Andes as our site, but after nine years, that's exactly where we ended up, the lines of the temple set against nothing but pure nature, and you turn around and you get nothing but the city below you, and inside, a view in all directions, radiating gardens from each of the alcoves, radiating paths.
Last October, the opening ceremonies -- a beautiful, sacred event, 5,000 people from 80 countries, a continuous river of visitors, indigenous people from all over South America, some who had never left their villages.
And of course, that this temple belongs to people, the collective, of many cultures and walks of life, many beliefs, and for me, what's most important is what it feels like on the inside; that it feel intimate, sacred, and that everyone is welcome.
And if even a few who come have the same reaction as that security guard, then it truly would be their temple.
And I would love that.
Thank you.
(Applause)